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MicroCal™ VP-ITC System - Chemical Instrumentation Facility

1. Troubleshooting 6 6 Troubleshooting Power LED not lit Check that power is plugged in and turned on Check Main VP ITC fuses Check that the control software is running and properly initialized Instrument is running Demo Mode Check seating of A D and D A boards in computer Check that the control software is installed and properly initialized Software reports networking errors Unplug network port from controller reboot and reload the control software Data shows problems Refill the reference cell Clean the cell and titration and loading syringes Check that the titration syringe needle is straight Run a known sample water or standard test kit If these steps do not resolve the problem see section Section 6 1 How to get help on page 64 Control software reports initialization Contact your GE Healthcare service errors communication problems or representative hardware errors not covered in this manual This section contains tips and information for troubleshooting the MicroCal VP ITC Many problems in instrument loading and cleaning show characteristic baseline and titration abnormalities and Knowing which system is affected can greatly speed the resolution of the issue Some problems can easily be corrected by the average user some may be corrected by the more advanced user and some require the expertise of a GE Healthcare service technician The GE Hea
2. 4 Gently push down on the top of the syringe until you feel it hit the bottom of the cell If you are unsure then double check it by lifting the syringe up and lowering it again until the bottom of the cell stops it 5 Lower the upper syringe clamp so that it is flush to the top of the syringe holder MicroCal VP ITC Operating Instructions 28 9639 79 AA 57 5 Maintenance 5 6 Y axis calibration check 6 Tighten the set screw of the upper syringe clamp so that the disk is fixed to the syringe glass 7 Raise the syringe by carefully prying up on the upper syringe clamp until it is approximately 2 3 mm the thickness of a US quarter higher than the top of the syringe holder 8 Loosen the set screw of the upper syringe clamp so that the clamp is free to slide up and down on the outer diameter of the glass bore Lower the syringe clamp all the way down so that it is again flush to the top of the syringe holder 9 Tighten the set screw of the upper syringe clamp The syringe height is now fixed at 2 3 mm from the bottom of the sample cell 5 6 Y axis calibration check 58 It is recommended that the y axis calibration be checked every few months to ensure accurate data acquisition The automatic calibration check routine will send a series of pulses to the cell heaters dissipating a known power The offset in the DP as a result of this power is analyzed in comparison to the correct DP offset It is recommended that Origin for real time
3. Instructions The Operating Instructions provide you with the instructions needed to handle MicroCal VP ITC in a safe way Prerequisites In order to operate MicroCal VP ITC safely and according to the intended purpose the following prerequisites must be met e You should have a general understanding of the use of a personal computer running Microsoft Windows in the version provided with your product e You should be acquainted with the use of general laboratory equipment and with handling of biological materials e You must read the Safety Instructions in Chapter 2 of these Operating Instructions e The system should be installed according to the instructions in Chapter 3 of these Operating Instructions e You should understand the concepts of titration calorimetry e You must read and understand these Operating Instructions In this chapter This chapter contains important user information and a general description of MicroCal VP ITC and its intended use MicroCal VP ITC Operating Instructions 28 9639 79 AA 5 1 Introduction 1 1 Important user information 1 1 Important user information Read this before using MicroCal VP ITC AR Xe All users must read the Safety Instructions in Chapter 2 of these Operating Instructions before installing using or maintaining the system Do not operate MicroCal VP ITC in any other way than described in the user documentation If you do you may be exposed to hazards th
4. manifested in many different ways it is not possible to recommend a power conditioner for all situations It is recommended that you test a power conditioner at your location before you purchase it If you believe you are experiencing power source related problems please contact a GE Healthcare field engineer Table 3 1 Power supply requirements AC Mains Requirements Specification Requirement Voltage Regulation 100 to 240 VAC Frequency 50 60 Hz Power 120 Watts Fuses 2 1 Amp 250 Volt Time Delay Protective earth terminals Internal External marked It is emphasized that room temperature fluctuations i e maximum 2 5 C due to the cycling on off of heating and cooling systems strong air currents sunlight directly on the instrument and through space electromagnetic waves may cause subtle performance problems Table 3 2 Environmental requirements Environmental Operating requirements Temperature 10 C to 28 C Humidity lt 70 RH Atmospheric Pressure 700 to 1060 hPa 3 2 Transport 26 CAUTION Lift the MicroCal VP ITC instrument in the upright position Do not use the front panel cover as a lifting handle Before moving the system MicroCal VP ITC Operating Instructions 28 9639 79 AA Installation 3 Unpacking 3 3 e Disconnect all cables and tubing connected to peripheral components and liquid containers e Remove all items from the top of the syst
5. Before starting the system make sure that there is no leakage Personal protection WARNING Always use protective glasses and other personal protective equipment PPE appropriate with the current application to ensure personal safety during operation WARNING The operator should always follow proper laboratory procedures in handling and disposing of volatile or hazardous solutions Please refer to MSDS requirements for chemical hazards and PPE requirements WARNING This instrument is used for a wide variety of experiments that can utilize potentially hazardous materials Use of these could cause exposure to biological chemical and radiation hazards depending on the user s experiments Users should educate themselves about the samples they are using to avoid these hazards gt Pee WARNING Contrad 70 Decon 90 is highly caustic and is increasingly active at elevated temperatures Use personal protective equipment for eyes skin and clothing All hazards are explained on the MSDS that arrives with the Contrad 70 Decon 90 MicroCal VP ITC Operating Instructions 28 9639 79 AA 17 2 Safety instructions 2 1 Safety precautions Installing and moving the instrument WARNING Power cord Only use power cords delivered or approved by GE Healthcare WARNING Do not block the ventilation inlets or outlets on the system WARNING Installing the controller The compute
6. ITC be turned off during extended periods of down time such as holidays and vacations The system should be cleaned after each run and be left clean when it is turned off Tip For quick start up leave instrument on and set to the desired experimental temperature MicroCal VP ITC Operating Instructions 28 9639 79 AA 47 4 Operation 4 7 Procedures after a run 48 MicroCal VP ITC Operating Instructions 28 9639 79 AA Maintenance 5 Cell cleaning 5 1 5 Maintenance Overview This section provides the user with information on the proper maintenance of the instrument to ensure proper function The maintenance requirements of the MicroCal VP ITC are simple but essential for quality experiments Please read and understand the entire set of instructions prior to performing maintenance Feel free to contact GE Healthcare with any questions or concerns The instructions in this manual are designed for a MicroCal VP ITC user who has used the instrument and therefore has a basic knowledge of the system e The cells injection and filling syringes must be kept clean The cells should then be left filled with water or buffer e The plunger tips for the pipette injection syringe must be replaced regularly to prevent excess wear that would allow the titrant to leak from the syringe e Y axis calibration should be confirmed annually e The temperature calibration should be confirmed annually e The syringe height i e position of the
7. VP ITC Operating Instructions 28 9639 79 AA Operation 4 Cleaning the cells using the ThermoVac 4 5 The ThermoVac in conjunction with the cell cleaning device may be used to circulate cleaning and rinsing solutions through the MicroCal VP ITC sample cell To clean the VP ITC cells Figure 4 7 Front view of MicroCal VP ITC Table 4 1 Parts in Figure 4 7 Part Description 1 Cell cleaning apparatus 2 Adapter 3 Soft tubing to beaker of detergent Soft tubing to flask Insert the cell cleaning apparatus into the adapter until the top flange is touching the top of the adapter see above Insert the long needle into the sample cell and push down carefully until the O ring has sealed Immerse the end of the upper tubing of the cell cleaning apparatus into a beaker of 200 400 mL of 20 Contrad 70 Connect the end of the lower tubing to a one liter vacuum flask through the 8 rubber stopper MicroCal VP ITC Operating Instructions 28 9639 79 AA 43 4 Operation 4 5 Cleaning the cells using the ThermoVac 5 Attach the side arm of the vacuum flask to the vacuum port on the ThermoVac See Figure 4 8 below a Figure 4 8 VP ITC cell cleaning Table 4 2 Parts in Figure 4 8 1 Cell cleaning apparatus 2 Plastic tubing 3 To vacuum pump of Thermovac 4 Hose with Luer lock connector 5 In line filter 6 Detergent solution 7 Vacuum port 6 Turn on t
8. aspects of MicroCal VP ITC operations NOTICE This chapter assumes a thorough knowledge of the topics discussed in all previous sections of this manual If you have not read these sections please do so before attempting this tutorial 4 1 Procedure before a run Note See Section 1 4 for contro software On Off instructions Turning the MicroCal VP ITC on Once the MicroCal VP ITC unit has been cabled to the PC it is ready to use At the rear of the unit is a power on off switch which functions as the master power switch and must be in the on position It can be turned to off when the MicroCal VP ITC will not be used for long periods of time i e weekends holidays etc NOTICE The user interface program VPViewer has to be running for the cell to function properly even though the power switch and the power LED are on Leaving the power on During frequent on periods the master power may be left on as long as the cell user interface program VPViewer is running The software automatically ensures that the system does not incur any damage and keeps the MicroCal VP ITC cell ready Periods of inactivity GE Healthcare recommends that the VPViewer application be closed and the master power be turned off when the system will not be used for extended periods of time 4 2 Basics of performing a run In order to perform a basic ITC titration experiment the user must load the samples into the
9. data be enabled for this check To begin the y axis calibration check procedure select VPViewer menu ITC Start ITC Calibration Run Y Axis Check System ITC Help Print S ave As Text Run Parameters Start ITC Calibration Run Figure 5 5 Menus Once the menu has been selected the Calibration Pulse Setup Window will appear This window allows the calibration pulses to be modified Individual pulse parameters are entered by first selecting a pulse or multiple pulses then entering the desired parameter value into the pulse parameter boxes Calibration Power Pulse Duration and Pulse spacing Users are encouraged to simply use the default y axis calibration MicroCal VP ITC Operating Instructions 28 9639 79 AA Maintenance 5 Y axis calibration check 5 6 parameters After the run and pulse parameters are entered clicking on the Start Run button will start the run The ITC will equilibrate in the same manner as it would during a titration experiment If creating customized calibration parameters users must be aware of the DP range limits when setting reference power and pulse sizes The reference power must be low enough to allow all pulses without hitting saturation and high enough to allow all pulses without crossing zero If a pulse size is too small it can show abnormally high error After the final equilibration phase has completed the initial delay will begin and the pulses will be applied as entered As each pulse comp
10. for help The water runs should be provided to the GE Healthcare service technician for evaluation Following the evaluation a representative from the service department will contact you with comments and recommendations MicroCal VP ITC Operating Instructions 28 9639 79 AA Reference information 7 Instrument Specifications 7 1 7 Reference information 7 1 Instrument Specifications Performance Specifications Operating Temperature Range 2 80 C Response Time 20 seconds Cell Design 1 4 mL coin shaped Titration Syringe 290 uL Smallest Injection Size 0 1 uL Stirring Rate 0 1000 r p m Physical Specifications Description Data Cell Material Hastelloy Alloy C 276 Dimensions Calorimeter 20 x 44 x 38 cm 8 x 17 x 15 in Controller 15 x 36 x 41cm 6 x 14 x16 in Monitor 38 x 40 x 20 cm 15 x 15 5 x 8 in Weight Calorimeter 12 kg 25 5 Ibs Controller 9 kg 20 Ibs Monitor 5 kg 10 Ibs For operation the MicroCal VP ITC with a computer controller requires about 1 2 meters of normal bench space ca 70 cm wide Electrical specifications Electrical specifications are for the calorimeter only Characteristic Data Voltage 100 to 240 Volts grounded Frequency 50 60 Hz MicroCal VP ITC Operating Instructions 28 9639 79 AA 65 7 Reference information 7 2 Ordering information Characteristic Data Power 120 Watts Fuses 2 1 00 A 250 V Tim
11. i Figure 3 4 Pipette assembly 6 injector 1 Pipette injector 2 Pipette locking collar 3 Syringe holder Note When the locking collar is fully tightened there should be only a couple threads of the pipette injector visible Plug the connector of the pipette into the back of the pipette controller stirring 7 base see Figure 3 2 to complete the pipette assembly 31 MicroCal VP ITC Operating Instructions 28 9639 79 AA 3 Installation Connect the power cord to the IEC 320 inlet power receptacle see Figure 3 5 below on the back of the ThermoVac Connect the power plug only to a main power supply receptacle with a 3 wire protective Earth ground and a Ground Fault Circuit Interrupter GFCl Connect the vacuum cap shown in Figure 3 5 to the port labeled Vacuum H Q w e TOIMII l 20 Figure 3 5 Rear panel controls Table 3 4 Rear panel of ThermoVac Part Description Power main switch Power fuses IEC 320 inlet power receptacle Vacuum port Pressure port After installation it is recommended that a titration of a known system be performed to test that the instrument has been installed correctly 3 5 Validation ThermoVac 1 2 3 4 5 3 5 Validation 32 MicroCal VP ITC Operating Instructions 28 9639 79 AA Operation 4 Procedure beforearun 4 1 4 Operation This chapter covers the basic
12. period for each injection At the bottom of this group MicroCal VP ITC Operating Instructions 28 9639 79 AA 39 4 Operation 44 Real time Origin is asummary table that lists these parameters ordered by injection number The user may select an injection to edit by clicking on a row to highlight it the parameters for this injection can be entered into the text boxes see below Then depending on the Edit Mode selected the user may edit the text boxes to effect all injections All Same only the currently highlighted injection Unique or the currently highlighted injection and all the following injections Apply To Rest nthe Volume box the user may enter the volume of titrant in uL to be injected from the pipette into the sample cell for the selected injection s n the Duration sec box the user may enter the time in seconds that the instrument will take to inject the titrant into the sample cell VPViewer will generally default this value to be twice the number entered in the Volume text box For Single Injection Method SIM experiments the standard duration is ten times the volume n the Spacing sec box the user may enter the time in seconds between the beginning of the selected injection and the beginning of the next injection or end of the run This spacing must allow enough time between the injections to allow the DP signal to return to the baseline after an injection peak deflection Typical values for this p
13. stir paddle from the bottom of the cell should be approximately 3 mm Once the syringe height adjustment is set it is not usually a problem but this distance is custom for each instrument This means that the user must set the height of newly purchased replacement syringes 5 1 Cell cleaning The cells must be cleaned routinely to maintain the high performance of the instrument Dirty cells will contribute greatly to cell filling problems repeatability problems and possibly misinterpretation of data Inadequate cleaning is the cause of most problems experienced with the MicroCal VP ITC The importance of adequate cleaning cannot be stressed enough The cleanliness of the syringes must not be overlooked including the injection and filling syringes see Section 5 2 The MicroCal VP ITC reference cell does not require special cleaning but should be rinsed and refilled with distilled water once a week See the buffer rinse instructions below There are three methods of cleaning the sample cell As a general rule the simplest effective method of cleaning is preferred The simplest method is manually rinsing the cell with buffer solution using the filling syringe this is adequate for most samples The second method involves using the ThermoVac and cleaning device and should be MicroCal VP ITC Operating Instructions 28 9639 79 AA 49 5 Maintenance 5 1 Cell cleaning Buffer Rinse performed after every 3 5 experiments after any sample
14. that precipitates and at the end of each day s experiments See section 4 5 for instructions on using the ThermoVac for cleaning the ITC sample cell The third method involves filling the cell with a cleaning solution and allowing it to soak at an elevated temperature The first two methods involve some physical agitation which is necessary to adequately clean the cell The soaking method generally uses an aggressive cleaning agent is used after the other methods have failed Rinsing with water after using any cleaning agent is important If the problems are not resolved after a high temperature soak please contact GE Healthcare NOTICE The instrument should be left clean if it will not be used again immediately NOTICE The VP ITC cells are constructed out of Hastelloy C 276 Hastelloy is extremely resistant to corrosion by strong bases but strong acids should be avoided NOTICE If the reservoir overflows during the cleaning procedure the fluid may contaminate the stir motor bearing and damage it beyond repair Care should be taken not to overfill the reservoir If internal contamination is suspected consult with GE Healthcare personnel for further recommendations O O This rinse should be performed before every run for the sample cell or once a week for the reference cell The sample cell should be rinsed with the buffer that will be used for the next run or water if that is not available The reference cel
15. tube holder it may be difficult to lift it out of the sample chamber In this case you may use a 3 32 hex allen key wrench to turn the screw located at the bottom of the center hole of the tube holder to lift the tube holder out 4 Turn the stirring on and adjust the speed 5 Turn on the vacuum Push the vacuum switch to the right towards timer to activate the vacuum for a preset 5 minutes duration Push the switch to the left to manually control the time for the vacuum 6 Place the vacuum cap on top of the sealing o ring The sound of the vacuum pump will change pitch to indicate the vacuum has sealed the Cap to the O ring Once the vacuum has sealed the Vacuum Cap will be held firmly in place until the vacuum pump shuts off 7 For the first few minutes after the vacuum pump is turned off the vacuum in the sample degassing chamber may remain fairly tight making the removal of the vacuum cap difficult During this period the easiest way to release the vacuum is to remove the tubing from the rear vacuum port or to twist off turn counter clockwise the in line filter 8 Observe the behavior of the sample under vacuum and adjust the bleeder valve as necessary to avoid the boiling of your sample 4 7 Procedures after a run The MicroCal VP ITC was designed to have its power on for extended periods of time This will keep the system electronics at the normal operating temperature It is recommended that the power of the MicroCal VP
16. 3 3 MicroCal VP ITC Operating Instructions 28 9639 79 AA 29 3 Installation 3 4 Setup 30 2 Insert the bottom syringe clamp over the syringe needle onto the glass part of the syringe a e 2 Figure 3 3 Pipette assembly Table 3 3 Parts in Figure 3 3 1 Pre mounted syringe clamp 2 Injection syringe 3 Syringe holder 4 Syringe clamp 5 0 050 Ball point hex driver 3 Make sure the top syringe clamp is still seated against the top of the syringe holder hold the bottom syringe clamp tightly against the bottom of the syringe holder and gently tighten the set screw using the accessory 0 050 hex driver NOTICE Do not overtighten the set screw as too much pressure will cause damage Tighten the screw gradually until the bottom syringe clamp can no longer move freely then stop tightening 4 Insert the syringe holder into the pipette holder attached to the side of the MicroCal VP ITC 5 Bring the pipette injector directly above the syringe holder start bringing the injector down while observing the plunger tip of the pipette injector to insure that itis being inserted into the hole in the glass barrel of the injector syringe then mate the screws of the pipette injector to the locking collar of the syringe holder MicroCal VP ITC Operating Instructions 28 9639 79 AA Installation 3 Setup 3 4 With your fingers turn the locking collar until it is fully tightened on the pipette
17. GE Healthcare MicroCal VP ITC System Operating Instructions Original Instructions Table of Contents Table of Contents MM 11 oo soo ene ee tae pee ne proelttrope rt rent in nenyeRtr cme entree es 5 1 1 Important user INFOMATION o eeeeseessssseteeesssssssssseeecceeeeseseseststttmntnnenenssssseseeeeeeeet 6 1 2 Regulatory IATOMIAGTION seseina a 7 L3 INSTPUMENT oes as 10 T4 Control SOLEWE ooppera 13 2 Safety instructionS s s sessessssessssssressssesseseeressssessesssesssse 15 2 1 Safety precautions wee LS 2 2 kabels one eeeceeecceeeeetetettteeeee ww 20 2 3 Emergency procedures aad ZA Recycling procedures eeeeeesssssssssssesecesecesstssssestsssssssseseeseseeseceeeetesisetemtensssseseett 23 3 WSROUUN OD siossiscdiasccasdicnecausioissuncsateriexcserelecacscscedisszerahasgeniaiiciac 25 3 1 SMO MSQUIFEMMOMES vasssscicnsshciatadiecsgchascachaasiecscetencteechesseddicsaetandaacnelileceddachualstecn 25 3 2 Transport we 26 33 WHA CIA Gs srie e 27 BiG SOUP A A T 27 35 Validation hessas R e ESA 32 4 ONETAN a S 33 41 lt Proced r before ATUN aiassacescacssnntssentdcecoseacossssctsvoneauluactaiondsdvenctsansielein sedttovete 33 4 2 BASICS OF performing GUN siisssisiisniiisinsinisiisinsiiiininsiinsins 33 4 3 BASIC VPViewer Controls aeeeeesessssssssssesseseccecesssesssetsssssssssseeeeeseececeeeeeeeneneseeeees 38 44 Real time Origin oeeeeeesesesssssetesssssecsscsseecececceeeeesees
18. MicroCal VP ITC Operating Instructions 28 9639 79 AA 27 3 Installation 3 4 Setup Connect 9 pin serial pipette cable The serial cable has two 9 pin serial connectors one connector is female and the other is male The female end is to be attached to the serial port Com 1 or Com A of the Computer Controller The male end is to be attached to the serial plug on the back of the pipette controller stirring base on the MicroCal VP ITC Note Failure to connect the serial connectors correctly will cause the MicroCal VP ITC system to not operate properly 1 Connect the female end of the serial cable to the Computer Controller at the serial port 2 Connect the male end of the serial cable to the serial connector on the back of the pipette controller stirring base on the MicroCal VP ITC see Figure 3 2 Note Earlier versions of the MicroCal VP ITC require a slightly different serial cable and connection sequence Contact GE Healthcare for further information Figure 3 2 Cable connections 28 MicroCal VP ITC Operating Instructions 28 9639 79 AA Installation 3 Setup 3 4 Connect the power cord to the IEC 320 inlet power receptacle see Figure 3 2 on the back of the cell Connect the power plug only to a main power supply receptacle with a 3 wire protective Earth ground and a Ground Fault Circuit Interrupter GFCI WARNING Provide proper electrical power to the instrument This should be 100 240 Volt 50 60 Hertz alternating curr
19. TC Operating Instructions 28 9639 79 AA Operation 4 Real time Origin 4 4 Pictured below is the main Origin window for MicroCal VP ITC data display om OM See Gah Cee dere lnm Puree aT os i aiao mint aei Aae a Aea n Eii sale CTrermostating TC 30S Figure 4 5 Real time Origin Part Description 1 ITC Cell status 2 ITC Numeric display 3 Buttons for ITC data display The ITC cell status the MicroCal VP ITC numeric display and the buttons for MicroCal VP ITC data tools as indicated above have been added for user convenience in viewing data generated by the MicroCal VP ITC Following is a description of each of these sets of tools MicroCal VP ITC Operating Instructions 28 9639 79 AA 41 4 Operation 4 5 Cleaning the cells using the ThermoVac Buttons for Data Display This group of buttons allows you to rescale the y axis by simply clicking on a single button Rescale To Show All shows all the data currently on the plot Auto View 1 will rescale the y axis so that the last DP data point plotted will be centered ona full scale determined by the entry in the Full Scale Auto View 1 text box in the Edit Ranges box see description below By default it is 0 1uCal sec Auto View 2 rescales the y axis to a second scale centered on the last DP data point plotted By default it is 1uCal sec Saved View 1 rescales the y axis to a specific range specified in the Edit Range box By default the r
20. The injector screw will retract into the pipette 9 Use compressed air to blow any shavings or debris off the tip 5 5 Syringe height adjustment Each titration syringe comes with a round height disk upper syringe clamp that will ultimately determine the height of the syringe paddle above the bottom of the cell once the syringe and syringe holder is inserted into the ITC sample cell This is a critical setting for ITC performance and depends on the exact configuration of the instrument The proper setting for the ITC syringe height is 2 3 mm off the bottom of the cell If you order a replacement syringe for the pipette you will need to adjust the syringe height Also if you are experiencing excessive noise with stirring and the paddle is not bent you may wish to readjust the height For this procedure the syringe holder should be removed from the pipette See section 5 3 1 Loosen the set screw on the upper syringe clamp so that the disk is free to slide up and down on the outer diameter of the syringe glass 2 Position the syringe in the syringe holder so that the tip of the syringe will not hit the bottom of the cell when the syringe holder assembly is inserted into the sample cell This can be easily accomplished by positioning the glass of the syringe so that it is flush to the bottom of the holder but not lower 3 Insert the syringe holder assembly into the sample cell compartment and properly seat the assembly into place
21. ange is 1 to 1yCal sec Saved View 2 rescales the y axis to a second specific range C fade Rescale Ranges Options ox By default the range is 10 to 10uCal sec Cancel Full Scale Auto View 1 0 1 Edit Ranges opens a window that contains parameters to Full Seale Auto View2 be used with the aforementioned buttons In addition to the Saved View 1 Mafi Auto View and Saved View entries which are described Saved View 1 Y Max 1 above the X Axis Options drop down list box controls the oN d 1e automatic re scaling of the x axis when the data exceeds Rete Mca for ld the X Axis time display range Disabled Takes no action X Axis Options Rescale m H Current data may be plotted off screen Rescale Extends Scroll Figure 4 6 Menus the maximum X Axis setting by 25 resulting in a larger display range Scroll Extends the minimum and maximum X Axis setting by 25 preserving the same range of the display but always displaying the most recently plotted data Click OK to exit and save any changes or Cancel to exit without saving any changes The ITC Main Display shows the same data channels as VPViewer cell temperature DP and DT The status bar shows the current state of the instrument and is the same as the VPViewer status bar 4 5 Cleaning the cells using the ThermoVac Note The MicroCal VP ITC cell cleaning device cannot be used in the reference cell See Section 5 1 42 MicroCal
22. arameter in high gain feedback mode range from 90 180 seconds depending on the size of the peak and the kinetics of the reaction For Single Injection Method the spacing should be 90 180 seconds greater than the duration i e volume 20 ul duration 200 seconds spacing 300 seconds The Filter Period sec is the time period in seconds in which the data channel conversions are averaged to produce a single data point for plotting and saving For fast reactions a filter period of 2 seconds is sufficient to obtain enough data points for representation of the peak for accurate integration of the area For monitoring of very long slow thermal processes the filter period may be increased accordingly to avoid accumulation of excess data points Although there may be a practical limit for a data set size only available disk space would limit the number of data points that VPViewer is able to collect and save 4 4 Real time Origin 40 Note Experimental data is automatically saved to disc itc file and does not need to be saved with in Real time Origin This section describes the functionality of Origin for real time display When the software is opened it will open the Origin project window VPITCPLOT OPJ for real time data display This project of Origin is dedicated to data display only and should not be used for data analysis Users should open a separate instance of Origin for ITC to perform data analysis MicroCal VP I
23. are saturated and these last few injections can be used for control heat information The single injection method uses one single longer injection The Cell Temperature box is used to set the desired run temperature for the experiment Most runs are performed between 25 C room temperature and 37 C human body temperature although the instrument s operating range is 2 C to 80 C Throughout an ITC experiment a small constant amount of power equal to the Reference Power entered is continuously supplied to the offset heater of the reference cell This causes the DP feedback system to become positive to supply compensating power to the sample cell that will equilibrate the temperatures During an experiment the DP baseline will equilibrate near the value entered in the Reference Power box The reference power setting is often referred to as the baseline setting The best choice for the reference power setting will be determined by the anticipated size and direction of the titration peaks Large exotherms will require a large reference power setting ca 5 uCal sec and large endotherms will require a very small reference power setting ca 0 5 uCal sec When working with an unknown sample a reference power of 2 3 uCal second is best The Initial Delay refers to the time in seconds after the instrument has started a run and before the first injection The standard parameter is 60 seconds this is necessary to establish a baseline prior
24. ass A control and laboratory use EN ISO 12100 1 Safety of machinery Basic Harmonized with 12100 2 concepts general principles and 2006 42 EC design EN ISO 14121 1 Safety of machinery Principles of Harmonized with 14121 2 risk assessment 2006 42 EC CE marking The CE marking and the corresponding Declaration of Conformity is valid for the instrument when it is e used as a stand alone unit or e connected to other CE marked instruments or e connected to other products recommended or described in the user documentation and e used in the same state as it was delivered from GE Healthcare except for alterations described in the user documentation or explicitly authorized by GE Healthcare 8 MicroCal VP ITC Operating Instructions 28 9639 79 AA Introduction 1 Regulatory information 1 2 Regulatory compliance of connected equipment Any equipment connected to MicroCal VP ITC should meet the safety requirements of EN 61010 1 IEC61010 1 or relevant harmonized standards Within the European Union connected equipment must be CE marked Instrument safety compliance specifications Microcal VP ITC calorimeters carry the CUE Safety Certification Mark authorized by TUV America a division of T V S ddeutschland to signify that AS S PRODUCT SERVICE c US 1 The instrument has been tested by an accredited Certification Body and meets applicable Canadian electrical safety standards requiremen
25. at can lead to personal injury and you may cause damage to the equipment Intended use The MicroCal VP ITC is an Isothermal Titration Calorimeter system designed for biomolecular interaction studies in research applications The MicroCal VP ITC system is intended for research use only and shall not be used in any clinical procedures or for diagnostic purposes Safety notices These Operating Instructions contain WARNINGS CAUTIONS and NOTICES concerning the use of the product with meanings as defined below WARNING WARNING indicates a hazardous situation which if not avoided could result in death or serious injury It is important not to proceed until all stated conditions are met and clearly understood CAUTION CAUTION indicates a hazardous situation which if not avoided could result in minor or moderate injury It is important not to proceed until all stated conditions are met and clearly understood NOTICE NOTICE indicates instructions that must be followed to avoid damage to the product or other equipment 6 MicroCal VP ITC Operating Instructions 28 9639 79 AA Introduction 1 Regulatory information 1 2 Notes and tips Note A Note is used to indicate information that is important for trouble free and optimal use of the product Tip A tip contains useful information that can improve or optimize your procedures Typographical conventions Software texts and commands are identified by b
26. button in the Setup Maintenance tab of VPViewer Note A bent injection syringe is a common problem inspect syringes for bends frequently Injection syringe s should always be stored in their wooden box Removing the syringe 52 1 The first step in removing the titration syringe is to decouple the syringe holder from the pipette by turning the locking collar until it completely unscrews and gently pulling the holder down until the two pieces come apart see Figure 5 1 2 Next remove the bottom locking ring from the syringe using a 0 050 hex driver DO NOT loosen the top locking ring it determines the height of the syringe in the cell MicroCal VP ITC Operating Instructions 28 9639 79 AA Maintenance 5 Replacing the titration syringe 5 3 and once the top locking ring has been loosened the height must be reset see section 5 1 3 Gently pull the top locking ring away from the syringe holder Since it is clamped to the syringe the syringe will come with it Pull the syringe all the way out being very careful not to bend the needle against the inside of the holder Set the syringe in a safe place z gt hes gt DN Ie Figure 5 1 Pipette assembly Table 5 1 Part in Figure 5 1 1 Pipette injector 2 Upper Syringe clamp 3 Pipette locking collar 4 Syringe holder 5 Lower syringe clamp Installing a new syringe The titration syringes are shipped and should be stored wit
27. cell and syringe set up the run parameters and click Start MicroCal VP ITC Operating Instructions 28 9639 79 AA 33 4 Operation 4 2 Basics of performing a run Cell filling The cells are filled using the long needled 2 5 mL glass syringe by filling from the bottom of the cell to the top The tops of the access tubes are visible within the cell port The sample cell is in the center and the reference is offset to the left as viewed from the front of the instrument 1 To load the sample cell gently insert the glass Hamilton syringe into the sample cell until it touches the bottom Pull up on the plunger until bubbles are being pulled from the cell and there is no more liquid Remove and empty the syringe Clean the syringe if necessary Pull approximately 1 8 mL of sample into the syringe and tap the syringe glass so that all air is at the top volume of the syringe Do not allow air to be put into the cells After removing the bubbles insert the syringe into the cell and gently touch the bottom of the cell with the tip of the syringe needle Raise the needle tip about 1 mm off the bottom of the cell and hold it there until finished filling Do not raise the syringe during the filling process Slowly inject solution into the cell until it spills out the top of the cell stem Finish the filling with several small abrupt spurts of solution to dislodge any bubbles in the cells Figure 4 1 Bubble space zone A Position
28. d into the software by 2 if the concentration was measured before the sample was introduced into the cell For further information on cell cleaning see Section 5 1 of this manual 4 6 Degassing samples using the ThermoVac Basic ThermoVac control STIRRER VACUUM SPEED Ee OFF OFF INCREASE icroCal ThermoVac SAMPLE TEMPERATURE TEMPERATURE 25 0 Figure 4 9 Front view of ThermoVac Vacuum The ThermoVac is capable of pulling a maximum vacuum of 28 4 inches of mercury 0 96 bar Push the VACUUM switch to the left towards ON to activate the vacuum pump The ThermoVac will maintain the vacuum until you return the switch to the off position MicroCal VP ITC Operating Instructions 28 9639 79 AA 45 4 Operation 4 6 Degassing samples using the ThermoVac 46 Push the VACUUM switch to the right towards timer to turn the vacuum pump timer on The timer function will initiate the vacuum and then automatically shut it off in approximately 5 minutes To end the vacuum cycle early push the switch to the ON position and back to the center Temperature The temperature dial controls the temperature in degrees Celsius C for thermostatting the sample chamber The rightmost digit sets the temperature value in tenths of a degree Sample temperature The sample temperature display shows the current temperature of the sample chamber Stir
29. de the instrument to stress Maintenance WARNING Replace fuses ONLY with same type fuses Several spare fuses are provided with the original shipment and the power receptacle is labeled with the correct type WARNING Repairs alterations or modifications must only be carried out by specialist personnel or with explicit directions from a GE Healthcare technician Removal or modification of any cover or component could result in an unsafe or easily damaged instrument The GE Healthcare service department will be happy to answer any questions and provide parts and service when necessary WARNING Only spare parts that are approved by GE Healthcare may be used for maintaining or servicing the system WARNING Disconnect power Always disconnect power from the from the instrument before replacing any component on the instrument unless stated otherwise in the user documentation WARNING Hazardous chemicals during maintenance When using hazardous chemicals for cleaning wash the system with a neutral solution in the last phase or step WARNING Decontaminate the equipment before decommissioning to ensure the removal of all hazardous residues PPP gt e 8 0 MicroCal VP ITC Operating Instructions 28 9639 79 AA 19 2 Safety instructions 2 2 Labels 2 2 Labels Labels on the instrument The illustration below shows an example of the identification labels attached to the r
30. e Delay Output Secondary Data Connection Only Protective Earth Terminals Internal external marked Mode of Operation Continuous Classification Class Environmental conditions Condition Characteristic Limits Operation Temperature 10 C to 28 C Humidity lt 70 RH Atmospheric pressure 700 to 1060 hPa Storage Temperature 20 C to 60 C no liquid in cells me Humidity lt 70 RH Atmospheric pressure 700 to 1060 hPa 7 2 Ordering information for ordering information visit www gelifesciences com microcal 66 MicroCal VP ITC Operating Instructions 28 9639 79 AA For local office contact information visit GE imagination at work and GE monogram are trademarks of General i Electric Company www gelifesciences com contact MicroCal and VP are trademarks of GE Healthcare companies Origin Any use of this software is subject to GE Healthcare Standard GE Healthcare Bio Sciences AB Software End User License Agreement for Life Sciences Software Products Bjorkgata n 30 All third party trademarks are the property of their respective owners 75184U ppsala 2010 General Electric Company All rights reserved Sweden First published Jan 2010 All goods and services are sold subject to the terms and conditions of sale 2 of the company within GE Healthcare which supplies them A copy of these www gel ifesciences com microcal terms and conditions is available on requ
31. e requirements 3 1 Installation NOTICE It is recommended that the installation of the MicroCal VP ITC instrument be performed by GE Healthcare personnel This section provides information about the installation of MicroCal VP ITC Figure 3 1 MicroCal VP ITC complete system Any equipment connected to the MicroCal VP ITC must fulfill applicable standards and local regulations Site requirements The MicroCal VP ITC with Computer Controller requires about 1 meter of normal bench space ca 70 cm wide This location should be away from strong drafts room temperature fluctuations intense sunlight vibrations and strong electrical or magnetic fields as may be produced by an NMR microwave oven large motors or refrigeration units In addition the mains power source 100 to 240 VAC should be properly grounded and free from voltage fluctuations harmonic distortions power dips and spikes The AC power line should be dedicated to the MicroCal VP ITC system and should not share that power with additional equipment MicroCal VP ITC Operating Instructions 28 9639 79 AA 25 3 Installation 3 2 Transport Although the power filtering in the MicroCal VP ITC instrument is adequate for most laboratory environments some disturbances may affect the performance of the instrument and it may be necessary to have the AC Mains power source evaluated see table below or install a power conditioner Since power source problems can be
32. e syringe 8 Empty the plastic loading syringe and reattach it to the port Remove the accessory plunger Reattach the plastic loading syringe 9 Apply vacuum to the glass end of the injection syringe using the vacuum tube attachment for approximately 10 minutes to dry the methanol BE SURE THE SYRINGE IS DRY If it is necessary the cleaning brush included with accessories may be used to scrub the inside diameter of the syringe glass Additionally there is a cleaning wire included with the ITC accessories that can be used to clean out the small delivery hole that is located on the very end of the twisted paddle of the titration syringe Cleaning the filling syringes 53 Cleaning the syringes may be accomplished by various methods The filling syringes are generally soaked in a cleaning solution and briefly scrubbed internally with a soft brush The filling syringes are then rinsed thoroughly at a sink with distilled water The syringes are often dried with HPLC grade methanol and a dry air or vacuum source They may also be left out to air dry but this method is not as reliable as forced drying Note If methanol is used to clean the syringe be sure to remove all residue of the methanol from the syringe Any methanol residue in the syringe will contaminate the next experiment Replacing the titration syringe Before replacing the titration syringe make sure that the pipette plunger is fully retracted by clicking the Open Fill Port
33. ear of the MicroCal VP ITC instrument t i i i Figure 2 1 Back panel of instrument ThermoVac The ThermoVac contains where appropriate safety symbols and labels as described below 20 MicroCal VP ITC Operating Instructions 28 9639 79 AA Safety instructions 2 Emergency procedures 2 3 Symbols used in safety labels The system complies with the requirements for electromagnetic compliance EMC in Australia and New Zealand Warning Read the user manual before using the system Do not open any covers or replace parts unless specifically stated in the user manual C The system complies with applicable European directives Labels concerning hazardous substances This symbol indicates that the waste of electrical and X electronic equipment must not be disposed as unsorted municipal waste and must be collected separately Please contact and authorized of the manufacturer for information concerning the decommissioning of equipment This symbol indicates that the product contains hazardous Tery materials in excess of the limits established by the Chinese AI standard SJ T11363 2006 Requirements for Concentration Limits for certain Hazardous Substances in Electronics 2 3 Emergency procedures In an emergency situation do as follows to stop the run Disconnect the equipment from the power outlet Power failure MicroCal VP ITC e The run is interrupted immediately in an undefi
34. em e Lift the system under the two sides 3 3 Unpacking The MicroCal VP ITC is delivered in protective packing material and shall be unpacked with great care Check the equipment for damage before starting assembly and installation Document any damage and contact your local GE Healthcare representative 5 4 Setup Arrange the components on the desktop similar to the picture of the system see Figure 3 1 The computer may be on either side depending on convenience Follow the instructions below for assembly CAUTION Lift the MicroCal VP ITC instrument in the upright position Do not use the front panel cover as a lifting handle CAUTION Before connecting the hardware make sure the controller PC is off gt Connect main data cable The main data cable connects the MicroCal VP ITC to the controller The cable is well labeled and has a single 37 pin female connector on one side marked Cell and two 37 pin female connectors on the other side marked J1 and J2 1 Plug the single 37 pin female connector marked Cell into the rear of the MicroCal VP ITC cell See Figure 3 2 below The two connectors on the split end of the cable are marked J1 and J2 and plug in to the PC 2 Plug the J2 connector into the A D board which is labeled J2 and is the slot on the left 3 Plug the J1 connector into the D A board which is labeled J1 and is the slot immediately to the right of the J2 slot
35. emperature calibration be checked approximately once every 12 months The measured temperatures should be within 0 2 degrees of the set temperatures in the VPViewer software There are two methods of checking the temperature calibration One requires a calibrated temperature probe the second uses the temperature standards included with the instrument The probe method is more accurate but requires the user to purchase the probe and keep it calibrated Temperature Probe This procedure requires a Control Company digital meter and submersible probe or equivalent The Control Company meter is model 9612 the probe is model 4021 The meter s calibration should be maintained to 0 05 C Make sure the cells have been cleaned and fill the sample cell with water Residue in the cells or empty cells will yield unpredictable results Insert the probe into the sample cell and turn the meter on 1 Use the Temperature control box under the Instrument Controls tab in VPViewer to set the temperature to 30 C 2 Set the Plot Idle Data flag so that the current data is displayed 3 When the instrument is thermostatting at the target temperature and the DT is O use the data reader tool and the display from the meter to take temperature data points as close together as possible 4 Repeat for the second check point at 70 C If the error for each is not less than 0 2 C please contact GE Healthcare for assistance It is recommended that users ke
36. ent with a Ground Fault Circuit Interrupter GFCI Some power strips including those provided by GE Healthcare contain a GFCI All power plugs and cords should be 3 prong grounded cables or outlets Assemble pipette The pipette assembly consists of the injection syringe with pre mounted top syringe clamp a bottom syringe clamp the syringe holder and the pipette injector NOTICE Take appropriate precautions to ensure that the long needle of the syringe is not bent If the needle is bent too far it will remain bent and the syringe will need to be replaced before proceeding with experiments NOTICE Never attempt to couple decouple the pipette from the syringe assembly unless the pipette plunger is in the open port position all the way up Failure to follow this recommendation may result in a bend in the pipette screw Even a slight bend will result in improper operation of the pipette To assemble the pipette please do the following please refer to diagrams in Figure 3 3 Note The height must be adjusted for any syringe that was not part of the original shipment of your MicroCal VP ITC instrument Please see Section 5 5 for instruction on adjusting the height of the syringe 1 Insert an injection syringe into the syringe holder until the top syringe clamp is firmly seated against the top of the syringe holder being careful not to bend the needle against the inside of the holder See Figure
37. ep a log with the date of the calibration check and the software and meter readings for each temperature point Temperature standards 60 The temperature standards are a pair of tubes each of which has a reservoir of wax in it The shorter sealed capillary tube contains Octadecane C18H3g Octadecane has an established melting point of 28 2 C The longer sealed capillary tube contains n Hexatriacontane C3gH74 which has an established melting point of 75 9 C Both the low and high temperature transitions are 100 reversible To use the standards run a calibration scan with a tube in each cell and check that the midpoint of the melting transition for each wax is within 0 2 C of the expected value 1 Make sure the sample and reference cells are clean and fill them with degassed water 2 Insert the low temperature capillary tube shorter into the sample cell and the high temperature capillary tube longer into the reference cell When facing the machine the longer tube goes on the left 3 Select VPViewer menu ITC Start ITC Calibration Run Temperature Check The ITC will thermostat at 22 C raise the shield temperature and scan simulating a DSC MicroCal VP ITC Operating Instructions 28 9639 79 AA Maintenance 5 Replacement of fuses 5 8 through low transition temperature region The DP will be recorded during the scan and saved It will then heat to 73 C raise the shield temperature and scan through the high transiti
38. est Contact your local Microcal representative for the most current information GE Healthcare UK Ltd Amersham Place Little Chalfont Buckinghamshire HP7 9NA UK GE Healthcare Bio Sciences Corp 800 Centennial Avenue P O Box 1327 Piscataway NJ 08855 1327 USA GE Healthcare Europe GmbH Munzinger Strasse 5 D 79111 Freiburg Germany GE Healthcare Japan Corporation Sanken Bldg 3 25 1 Hyakunincho Shinjuku ku Tokyo 169 0073 Japan imagination at work 28 9639 79 AA 01 2010
39. h the top locking ring in place If this syringe has not been used in this instrument before the top locking ring should be adjusted see Section 5 5 1 Insert the injection syringe into the syringe holder until the top syringe clamp is firmly seated against the top of the syringe holder being careful not to bend the needle against the inside of the holder See Figure 5 2 MicroCal VP ITC Operating Instructions 28 9639 79 AA 53 5 Maintenance 5 3 Replacing the titration syringe 2 Insert the bottom syringe clamp over the syringe needle onto the glass part of the syringe 1 N Figure 5 2 Pipette assembly Table 5 2 Part in Figure 5 2 1 Pre mounted syringe clamp 2 Syringe holder 3 Syringe clamp 4 050 ball point hex driver 3 Make sure the top syringe clamp is still seated against the top of the syringe holder hold the bottom syringe clamp tightly against the bottom of the syringe holder and gently tighten the set screw using the accessory 0 050 hex driver NOTICE Do not overtighten the set screw as too much pressure will cause damage Tighten the screw gradually until the bottom syringe clamp can no longer move freely then stop tightening 4 Bring the pipette injector directly above the syringe holder start bringing the injector down while observing the plunger tip of the pipette injector to insure that itis being inserted into the hole in the glass barrel of the injector sy
40. he ThermoVac vacuum pump The vacuum will pull the detergent solution from the beaker through the cell and into the waste flask NOTICE If the level of fluid in the waste flask reaches the level of the side arm the fluid will be drawn into the ThermoVac pump and will cause damage to the pump Do not allow the level of fluid in the waste flask to reach the side arm 7 Once sufficient detergent solution has passed through the cell remove the hose from the detergent solution and rinse it off using a plastic water bottle Then place the hose into another beaker containing 200 400 mL of water for rinsing 44 MicroCal VP ITC Operating Instructions 28 9639 79 AA Operation 4 Degassing samples using the ThermoVac 4 6 8 After rinsing with water remove the tube from the rinse water and allow time for the vacuum to drain the fluid out of the hoses then remove the cleaning apparatus from the cell 9 Remove the remaining water from the cell by using a long needle syringe If there is any residual soap in the cell reservoir be sure to rinse it clean with a long needle syringe and water Note We donot recommend drying the cell before filling with the sample solution but it should be rinsed twice with the buffer used for the next experiment Note A small amount of the buffer used for final rinsing will adhere to the walls of the cell and act to dilute your sample solution To correct for this lower the sample concentration entere
41. he pipette will depress the plunger of the filling syringe to inject the sample back into the filling test tube then raise the plunger to refill the injection syringe When the movement is complete the tip of the injection syringe will be positioned to its original position just below the filling port 14 Click on the Purge gt ReFill button again to repeat the purge refill action 36 MicroCal VP ITC Operating Instructions 28 9639 79 AA 15 16 17 18 Operation 4 Basics of performing a run 4 2 The purpose of both purge refill procedures is to dislodge any air bubbles from inside walls of the injection syringe which may have occurred during the first filling and expel them back into the titrant solution Carefully remove the pipette from its stand by picking it straight up avoiding bending the long needle Carefully move the pipette so that it is directly above the centered sample cell stem this is the hole on the right Carefully insert the pipette into the sample cell stem Watch the end paddle of the long needle to insure it is inserted directly into the access hole hold the pipette vertical and slowly lower the pipette When the pipette is almost completely inserted push down slowly and firmly to seat the pipette Enter the desired run parameters into the VPViewer control software see Section 4 3 for more information and click Start on the main toolbar to start the run Real time data will be displayed in the Or
42. heat is released or absorbed in direct proportion to the amount of binding that occurs When the macromolecule in the cell becomes saturated with added ligand the heat signal diminishes until only the background heat of dilution is observed With the MicroCal VP ITC system the entire experiment takes place under computer control The user inputs the experimental parameters temperature number of injections injection volumes and the computer carries out the experiment Origin software is then used to analyze the ITC data using fitting models to calculate reaction stoichiometry n binding constant Kp enthalpy AH and entropy AS The MicroCal VP ITC is delivered with a ThermoVac so that you can easily degas samples The ThermoVac is capable of thermostatting a sample at any temperature MicroCal VP ITC Operating Instructions 28 9639 79 AA 11 1 Introduction 1 3 Instrument from 0 C to 80 C pulling a vacuum of 28 4 inches of mercuryl 0 96 bar and stirring the sample using small magnetic stir bars The ThermoVac is also used to aggressively clean the MicroCal VP ITC cells Section 5 4 STIRRER SPEED SAMPLE TEMPERATURE TEMPERATURE 2 5 0 S OFF INCREASE MicroCal ThermoVac Figure 1 2 Front view of ThermoVac Part Description VACUUM 1 Filter 2 Luer lock connector 3 Vacuum cover 4 Current tem
43. igin window Once a run has completed the system should be promptly cleaned See sections 5 1 and 5 2 for cleaning information MicroCal VP ITC Operating Instructions 28 9639 79 AA 37 4 Operation 4 3 Basic VPViewer controls 4 3 Basic VPViewer controls 38 VPViewer2000 Default User System ITC Help gt amp Ee zi Load Run File Save Run File Thermostatting ITC 25 C Temp C DP Calis DT C 25 0 0 020 0 000 ITC Controls Thermostat Calib Experimental Parameters Injection Parameters Total Injections Volume pl Cell Temperature C Duration sec Reference Power pCal sec 1 34 4 Spacing sec Initial Delay sec Filter Period sec Syringe Concentration mM Edit Mode Cell Concentration mM GA Same Unique Apoly To Rest Stunting Speed Data File Name EDNewS6a ite Feedback Mode Gain None Low ITC Equilibration Options No Check k Tes zi Fast Equil m Pipette Controls ________ i Data File Comments il ae a ga BES eg e Close Fill Pott ines C ul 2 Figure 4 4 VPViewer The commonly used controls within VPViewer are in the ITC Controls tab The top bar above this tab contains several buttons for opening saving and viewing run parameter files The Load Run File button will display the file open dialog box in which the user can select a file to load into the tab Run parameters may be loaded from one of two types of files a previous e
44. l should always be rinsed with water Empty the cell s fill the loading syringe with water or buffer and inject liquid into the cell until it begins to spill out into the reservoir Pull the liquid back into the syringe and then cycle it in and out of the cell several times Remove all of the liquid from the cell and reservoir empty the loading syringe and refill it with fresh water or buffer Repeat several times ThermoVac detergent clean Vigorous ITC method 50 See section 4 5 cell cleaning When the cells are at room temperature or below fill the cells with a 20 solution of Contrad 70 Decon 90 raise the temperature to 65 C and let stand for one hour Contrad 70 Decon 90 is a detergent manufactured by Decon Laboratories and MicroCal VP ITC Operating Instructions 28 9639 79 AA Maintenance 5 Cleaning the syringes 5 2 contains dodecylbenzensulfonic acid potassium hydroxide sodium citrate and sodium laurel ether sulfate WARNING Contrad 70 Decon 90 is highly caustic and is increasingly active at elevated temperatures Use personal protective equipment for eyes skin and clothing All hazards are explained on the MSDS that arrives with the Contrad 70 Decon 90 Cool the cells to room temperature then remove and dispose of the Contrad 70 Decon 90 Follow with a thorough rinse with distilled water see section 4 5 for instructions for using the ThermoVac CAUTION Removing liquid from
45. letes Origin will analyze the pulse region and determine the deflection of the baseline as well as the energy area of the pulse The requested power and energy will also be displayed as will a percent error for both power and energy The reported error in deflection or energy should be less than 1 If the error is reported as higher than 1 please contact GE Healthcare For a more rigorous analysis once the calibration is done and the system is thermostatting again open the ITC Calibrations project Click on the Y Axis Calibration DP uCal sec button Origin will ask for the DP check file Select the data file just created and click Open The computer will pause for a few moments If any of the pulses are out of specifications a pop up will inform you It will ask you to save OP uCal sec Figure 5 6 Raw data from Y axis calibration check Origin will show four graphs The upper left graph holds the raw data The lower two graphs show the energy and power of each pulse The upper right graph displays the percent error for the energy and power of each pulse Right click at the upper right portion of the graph and select Go To Window from the menu Check the sizes of the errors If any of the errors is greater than 1 please contact GE Healthcare MicroCal VP ITC Operating Instructions 28 9639 79 AA 59 5 Maintenance 5 7 Temperature calibration check 5 7 Temperature calibration check Itis recommended that the ITC t
46. lthcare service department is happy to provide any advice parts or service that may be necessary MicroCal VP ITC Operating Instructions 28 9639 79 AA 63 6 Troubleshooting 6 1 6 1 64 How to get help How to get help Please contact us for any instrument or data analysis questions or issues you may have For contact information for your local office please visit www gelifesciences com contact or for MicroCal specific information visit www gelifesciences com microcal When e mailing for technical assistance if possible please attach a recent data file s itc raw ITC data file that demonstrates the problem Also please include all details that may be relevant to the problem For instance where the problem or question relates to post run data analysis it is best to attach both the raw data file itc and the Origin project file opj generated during data analysis There are two general categories of troubleshooting for the MicroCal VP ITC and its operation The most extreme category is when a system is not working at all Problems that prevent users from operating the instrument require immediate consultation with a GE Healthcare technician Customers should not attempt to repair the hardware or software unless instructed to do so by a GE Healthcare service representative The second and less extreme general category of a problem is when a MicroCal VP ITC instrument is functioning but is not operating within i
47. me of the cell is only 1 4 mL Figure 1 1 Principle drawing Description 1 Sensor MicroCal VP ITC Operating Instructions 28 9639 79 AA ThermoVac Introduction 1 Instrument 1 3 Part Description 2 Sensor 3 Inner shield 4 Reference cell 5 Lead screw 6 Injector 7 Plunger 8 Stirring 9 Syringe 10 Outer shield 11 Sample cell Temperature differences between the reference cell and the sample cell are measured calibrated to power units and displayed to the user as well as saved to disk The data channel is referred to as the DP signal or the differential power between the reference cell and the sample cell This signal is sometimes thought of as the feedback power used to maintain temperature equilibrium Calibration of this signal is obtained electrically by administering a known quantity of power through a resistive heater element located on the cell In a typical experiment the syringe containing a ligand is titrated injected into the cell containing a solution of macromolecule An injection which results in the evolution of heat exothermic within the sample cell causes a negative change in the DP power since the heat evolved chemically provides heat that the DP feedback is no longer required to provide The opposite is true for endothermic reactions Since the DP has units of power the time integral of the peak yields a measurement of thermal energy AH This
48. nd NOTICE Be careful not to hit the long needle of the injection syringe against any object as this could cause the needle to bend and expel some solution from the syringe and result in a poor first injection for the experiment If the long needle is bent far enough it may cause a permanent deformation in the needle making the syringe unusable for future experiments MicroCal VP ITC Operating Instructions 28 9639 79 AA 35 4 Operation 4 2 Basics of performing a run VP ITC MicroCuorumter Figure 4 3 Pipette loading 4 Select the ITC Controls tab In the lower right corner is the Pipette Controls button 5 Click on the Open Fill Port button 6 The pipette will move the plunger of the injection syringe until the Teflon tip is just above the filling port of the syringe 7 Attach the tubing of the plastic filling syringe to the filling port of the injection syringe 8 Slowly withdraw the plunger of the plastic filling syringe to draw up the titrant solution until you see the solution exit through the top filling port 9 Click on the Close Fill Port button as soon as liquid begins to exit the top filling port 10 The pipette will lower the plunger of the injection syringe until the white Teflon tip is completely below the filling port 4mm 11 Remove the tubing of the plastic filling syringe from the filling port of the injection syringe 12 Click on the Purge gt ReFill button 13 T
49. ned state e The data collected up to the time of the power failure is saved MicroCal VP ITC Operating Instructions 28 9639 79 AA 21 2 Safety instructions 2 3 Emergency procedures Controller e The controller shuts down in an undefined state e The MicroCal VP ITC run is interrupted immediately in an undefined state 22 MicroCal VP ITC Operating Instructions 28 9639 79 AA Safety instructions 2 Recycling procedures 2 4 2 4 Recycling procedures The equipment shall be decontaminated before decommissioning and all local regulations shall be followed with regard to scrapping of the equipment Disposal general instructions When taking the MicroCal VP ITC system out of service the different materials must be separated and recycled according to national and local environmental regulations Recycling of hazardous substances The MicroCal VP ITC instrument contains hazardous substances Detailed information is available from your GE Healthcare representative Disposal of electrical components Waste of electrical and electronic equipment must not be disposed as unsorted municipal waste and must be collected separately Please contact an authorized representative of GE Healthcare for information concerning the decommissioning of equipment MicroCal VP ITC Operating Instructions 28 9639 79 AA 23 2 Safety instructions 2 4 Recycling procedures 24 MicroCal VP ITC Operating Instructions 28 9639 79 AA Installation 3 Sit
50. ng transfer to the calorimetric cells Note The filling syringe itself will act to change the sample temperature during cell filling For this reason users may consider using a cold syringe stored in a refrigerator to minimize the sample temperature change during cell filling The temperature of the injection syringe sample has little effect on the equilibration period Note The ThermoVac includes a preinstalled bleeder valve on the top of the vacuum cap to allow manual adjustment of the vacuum strength in the degassing chamber If the vacuum is boiling the sample in the chamber users should adjust the adjusting knob of the bleeder valve counterclockwise to reduce the vacuum Any customers with a ThermoVac that does not include this option may request one by contacting their local GE Healthcare office MicroCal VP ITC Operating Instructions 28 9639 79 AA Operation 4 Procedures after a run 4 7 To degas the solutions 1 Turn on the power switch 2 Set the desired temperature for the solution 3 Place your solution to be degassed into a test tube add a small stir bar and place the tube into one of the open cylinders of the Tube Holder insert Note To conserve titrant sample for loading into the injection syringe use the small test tubes provided with the ThermovVac Note Ifyou wish to use a tube or beaker larger than will fit into the tube holders you may remove the tube holder by simply lifting it up Due to the tight fit of the
51. old italic text A colon is used to separate menu levels e g File Open refers to the Open option in the File menu 1 2 Regulatory information This section lists the directives and standards that are fulfilled by MicroCal VP ITC Manufacturing information Requirement Content Name and address of manufacturer GE Healthcare Microcal Products Group 22 Industrial Drive East Northampton Massachusetts 01060 USA Place and date of declaration Northampton Massachusetts USA January 2010 Identity of person authorized to sign See EC Declaration of Conformity Declaration of Conformity Date of manufacture and serial The serial number contains the number code for the year of the manufacture of the instrument The serial number takes the form of xx yy zzz where yy year of manufacture CE Conformity Directive Title 2006 42 EC Machinery Directive MD 2006 95 EC Low Voltage Directive LVD MicroCal VP ITC Operating Instructions 28 9639 79 AA 7 1 Introduction 1 2 Regulatory information Directive 2004 108 EC ElectroMagnetic Compatibility EMC Directive International standards Standard Description Notes EN 61010 1 Safety requirements for electrical IEC 61010 1 equipment for measurement CAN CSA C22 2 control and laboratory use no 61010 1 EN 61326 1 EMC emissions and immunity Harmonized with CISPR Group 1 requirements for measurement 2004 108 EC Cl
52. on temperature region The DP will be recorded during the scan and saved 4 To evaluate the results open the ITC Calibrations Origin project 5 Click on the Temperature Calibration button 6 Origin will pause for several seconds Once it has finished it will ask you to save The default file name is usually acceptable it will be TCALREPORTYYMMDD Press ENTER to save 7 Origin will display a final report with a graph of each melting transition A text box on each graph gives the instrument serial number time and date that the report was generated expected midpoint actual midpoint and error It will then say if the result is within specifications or not If the results are not within specifications please contact GE Healthcare for instructions 5 8 Replacement of fuses WARNING Always disconnect power from the instrument before replacing fuses Replace fuses ONLY with same type fuses Several spare fuses are provided with the original shipment and the power receptacle is labeled with the correct type WARNING The MicroCal VP ITC contains two fuses found in the power receptacle at the rear of the instrument below the power switch and above the plug If the fuses repeatedly blow unplug the instrument and contact your local GE Healthcare representative MicroCal VP ITC Operating Instructions 28 9639 79 AA 61 5 Maintenance 5 8 Replacement of fuses 62 MicroCal VP ITC Operating Instructions 28 9639 79 AA
53. perature 5 Set temperature 6 Vacuum power switch rs Magnetic stirring RPM 12 MicroCal VP ITC Operating Instructions 28 9639 79 AA Introduction 1 Control software 1 4 Figure 1 3 ThermoVac top view Part Description 1 Tube holder 2 Vacuum sealing O ring 3 Tube holder removal screw 4 Vacuum cover 5 In Line filter 6 Vacuum port 1 4 Control software VPViewer 2000 In order for the system to initialize properly all components must be powered up in the correct order First boot up the computer and log in to Windows Once Windows has started power on the MicroCal VP ITC by operating the switch at the rear of the unit After several seconds open the MicroCal VP ITC user interface software called VPViewer This software controls the function of the ITC itself A real time copy of Origin will open automatically as well as VPViewer This copy of Origin is reserved for real time data display so for analysis the user should open a separate instance MicroCal VP ITC Operating Instructions 28 9639 79 AA 13 1 Introduction 1 4 Control software At startup the line just below the menus will read System Initiation Please Wait which is the current status of the instrument After a few seconds the system will begin heating or cooling to the preset temperature and the power LED on the front of the cell will light 14 MicroCal VP ITC Operating Instructions 28 9639 79 AA Safe
54. r should be installed and used according to the instructions provided in the documentation included in the shipment WARNING Replace fuses ONLY with the same type and rating as the fuses provided in the original shipment WARNING Access to power switch and power cord Do not block the rear and side panel of the instrument The Power switch must always be easy to access The power cord must always be easy to disconnect OP Pee NOTICE Disconnect power To prevent equipment damage always disconnect power from the MicroCal VP ITC before an instrument is removed or installed or a cable is connected or disconnected System operation 18 WARNING All solutions in the cells must be cooled down below 40 C before removal Any higher temperature may cause the syringe to break and will increase the dangers of most hazardous solutions gt gt WARNING Do not place vessels containing liquid on top of the instrument Spilled liquid is an electrical hazard MicroCal VP ITC Operating Instructions 28 9639 79 AA Safety instructions 2 Safety precautions 2 1 NOTICE Never allow liquid in the cells to freeze The expansion of the liquid can distort the cells and rupture the most critical sensor causing irreparable damage NOTICE The MicroCal VP ITC instrument should always be moved in its normal operating orientation Other orientations will subject delicate sensors insi
55. rer speed The stirrer speed switch activates a rotating magnetic field that will stir the sample when a small magnetic stir bar is placed in the tube containing the sample The speed ranges from 0 RPM OFF to the maximum speed of 800 RPM full turn clockwise Degas cell and syringe samples that may contain dissolved gas to ensure their bubble free loading This is particularly important if samples recently were recently refrigerated A ThermoVac sample degassing and thermostat station is provided with each instrument The ThermoVac s preset vacuum time of 5 minutes is adequate to degas a sample that is being stirred but a much longer time is required without stirring The standard practice is to set the ThermoVac temperature to 1 to 5 degrees below the intended experimental temperature while degassing If volatile buffers or ligands are being used then solutions should be prepared from degassed or pre boiled water and stored air free If sample solutions contain any undissolved solutes or extraneous solid material of other types they should be filtered before use Note To prevent a long equilibration time when running experiments below the ambient temperature load the sample at a temperature that is at or below the ambient temperature When using the ThermoVac for an experiment that is below the ambient temperature set the ThermoVac s temperature to 5 degrees below room temperature to compensate for the temperature change that can occur duri
56. ringe then mate the screws of the pipette injector to the locking collar of the syringe holder 54 MicroCal VP ITC Operating Instructions 28 9639 79 AA Maintenance 5 Replacing the titration syringe 5 3 5 With your fingers turn the locking collar until it is fully tightened on the pipette 2 3 Figure 5 3 Pipette assembly Table 5 3 Parts in Figure 5 3 1 Pipette injector 2 Pipette locking collar 3 Syringe holder When the locking collar is fully tightened there should be only a few threads visible on the pipette MicroCal VP ITC Operating Instructions 28 9639 79 AA 55 5 5 4 Maintenance Replacing the plunger tip 5 4 Replacing the plunger tip 56 The plunger tip inside the pipette can become worn over time GE Healthcare recommends replacing the tip every month or two or when the tip is visibly worn or damaged Note A worn plunger tip can cause the injection syringe to leak solution after loading Figure 5 4 Pipette with guide sleeve Table 5 4 Part in Figure 5 4 1 Threaded cap 2 Guide sleeve 3 Plunger tip 4 Pipette injector For this procedure the syringe holder should be removed from the pipette See section 5 3 NOTICE Be careful at all times when the pipette is not attached to the syringe holder not to damage or bend the injector screw as that will make the pipette unusable 1 Insert the white plastic g
57. s should be 100 240 Volt 50 60 Hertz alternating current with a Ground Fault Circuit Interrupter GFCI Some power strips including those provided by GE Healthcare contain a GFCI All power plugs and cords should be 3 prong grounded cables or outlets WARNING In case of fire unplug instrument Make sure the rear power connector is always accessible WARNING Do not operate the MicroCal VP ITC in any other way than described in the MicroCal VP ITC manuals WARNING Use caution when using solutions near the instrument If any liquid is spilled on or around the instrument unplug the instrument immediately and wipe it up If there is any possibility that liquid may have leaked into the instrument case contact GE Healthcare immediately Do not plug the instrument into any electrical outlet until the problem is resolved WARNING This instrument is not designed to the Medical Devices Directive 93 42 EEC and should not be used for medical purposes and or in the diagnosis of patients oP PPP gt NOTICE The MicroCal VP ITC cells are constructed out of Hastalloy Strong acids must be avoided Using flammable liquids 16 gt WARNING A fume hood or similar ventilation system shall be used when flammable or noxious substances are used MicroCal VP ITC Operating Instructions 28 9639 79 AA Safety instructions 2 Safety precautions 2 1 gt WARNING Fire Hazard
58. stenstnssnnssssseeeeececeeeeeeeeesesstntetteet 40 4 5 Cleaning the cells using the ThermoVac wee 42 4 6 Degassing samples using the THEFMOVAC essssssseeceesssessssseseeeeeeeeeeee 45 G7 Proced resafter CCU z sceciascaciacassszssensccosesensescienasscosstaacinnsbencadcechannaneapspnicnie 47 5 UWMOUNESM NCS es ccccoszecczcsstccszereschentescsesacestxeatecsieestiszeestesseteaceatts 49 5 1 Cell Cleaning eee we 49 5 2 Cleaning the syringes aol 5 3 Replacing the titration syringe e52 54 Replacing the PlUNGer tip on eesssssssessseeessssssccscseesseeeeeeeesetestmtsesssssseceeeeet 56 5 5 Syringe height adjustment on eeesssssssesesteseteessnsssseseeseeceeeeeeeeseessttientensnsseeseet 57 5 6 Y axis calibration check 58 5 7 Temperature Calibration CHECK o eeessssssesesssssessessseeceseeeesesssesstmusnsenssssste 59 5 8 Replacement Of FUSES oaeeeeeeesssssssssssssseessensssssesssssseeeeeeeeesesssessientensssseet 61 6 Troubleshooting sirieias ana never 63 61 Howto get help sstetsces cncicescdeestatddadainastistesdie T ER 64 MicroCal VP ITC Operating Instructions 28 9639 79 AA 3 Table of Contents 7 Reference IMPONIGTION ssccissess caccsessvesssaracccassesussancssszessessvasseies 7 1 Instrument Specifications 7 2 Ordering INfOrmation eeesssssesssssssessecssssssssscccesseeesececeseeesssuestetsssssssseeeeeeeseeeeeeet MicroCal VP ITC Operating Instructions 28 9639 79 AA Introduction 1 1 Introduction Purpose of the Operating
59. the cell when it is above 40 C may cause the glass syringe to shatter 5 2 Cleaning the syringes Cleaning the titration syringe WARNING Methanol is toxic If ingested as little as 10 mL can cause permanent blindness by destruction of the optic nerve and 30 mL is potentially fatal Methanol is volatile and care should be taken to seal vessels that contain methanol NOTICE Take care to avoid bending the syringe during this procedure NOTICE Do not attempt to clean the syringe holder with methanol This may inadvertently remove the syringe holder s internal lubrication 0 O 1 Disconnect the syringe from the pipette see Section 5 3 and insert the accessory plunger into the top of the syringe 2 Attach the plastic loading syringe tube to the filling port at the top of the syringe 3 Insert the tip of the injection syringe into the cleaning solution and draw 2 mL of solution through the syringe 4 Empty the plastic loading syringe and repeat the above step at least two more times MicroCal VP ITC Operating Instructions 28 9639 79 AA 51 5 5 3 Maintenance Replacing the titration syringe 5 Insert the tip of the injection syringe into distilled water and draw 2 mL of solution through the syringe 6 Empty the plastic loading syringe and repeat the above step at least two more times 7 Insert the tip of the injection syringe into HPLC Grade methanol and draw 2 mL of solution through th
60. to the first injection The Syringe Concentration and Cell Concentration boxes are a place to enter the experimental concentrations These concentration values are stored in the data file header and used for ITC data analysis These values are used only during data analysis and an entry is not required to perform an experiment Concentration can be entered and edited during post run data analysis in Origin Select the desired stirring rate from the drop down list 300 RPM is recommended for most ITC experiments If the solution in the sample cell contains suspended particles e g agarose beads then faster stirring may be necessary In the Feedback Mode Gain section the three available modes are none low or high High is recommended for most ITC experiments The feedback modes can be described as active low or high or passive none High gain will provide the fastest response time while passive mode none will provide the highest sensitivity Almost all ITC reactions will require using the high gain feedback mode Monitoring of long slow thermal process in the MicroCal VP ITC i e kinetics metabolic rates might benefit from using the passive or low gain feedback modes The Data File Comments box allows the user to enter comments about the experiment to be saved in the header of the data file for future reference The Injection Parameters group allows the user to define the volume duration spacing between injections and the filter
61. ts CSA SCC 2 The instrument has been tested by an NRTL Nationally Recognized Testing Laboratory and meets applicable United States electrical safety standards requirements ANSI UL The instrument has been tested by a Competent and Notified Body for applicable EU Directives and meets applicable safety standards requirements EN IEC MicroCal VP ITC Operating Instructions 28 9639 79 AA 9 1 Ls 15 10 Introduction Instrument Instrument The MicroCal VP ITC Isothermal Titration Calorimeter unit directly measures heat evolved or absorbed in liquid samples as a result of mixing precise amounts of reactants A spinning syringe is utilized for injecting and mixing of reactants Spin rates are user selectable the usual range is 0 to 1000 rpm The normal temperature operating range is 2 C to 80 C Wetted cell surfaces are Hastelloy which are resistant to most solutions however strong acids should be avoided Sample and reference cells are accessible for filling and cleaning through the top of the unit The sample cell is on the right as one faces the front of the unit A pair of identical coin shaped cells is enclosed within two shields the inner shield is referred to as the jacket Access stems extend from the top exterior of the instrument to the cells Both the coin shaped cells and the access stems are completely filled with liquid during operation This requires approximately 1 8 mL per cell even though the working volu
62. ts normal performance specifications Large baseline drifting non repeatable control peaks water water and or an increase in short term noise level are examples of performance problems These problems may be corrected by the operator in most cases For these types of performance issues it is recommended that customers carry out the following minimum diagnostic steps prior to requesting service 1 Thoroughly clean the cells Do not assume they are clean build up or unexpected sample residue will cause problems As a minimum use the provided cell cleaning apparatus to pass 500 mL of 20 Contrad 70 in water solution followed by 500 mL of cold water rinse through the sample cell Discretion may call for a more rigorous cleaning procedure 2 Using a clean Hamilton syringe refill both the reference and sample cells with filtered degassed water 3 Thoroughly clean the titration syringe or use a different syringe and load it with water 4 Activate the extended data mode by clicking the Extended Data Mode box in the Setup Maintenance tab While the software is in the extended data mode the ITC data files will contain all available information produced by MicroCal VP ITC This additional information will often help the MicroCal technician diagnose problems 5 Carry out a minimum of 25 10uL injections of water into water If after completion of the steps listed above the ITC performance is not corrected please contact the service department
63. ty instructions 2 Safety precautions 2 1 2 Safety instructions The points below are intended to enhance your safety awareness and to draw your attention to risks which only you the operator can prevent While GE Healthcare works to ensure that the instrument is designed and tested to be as safe as possible proper handling is also critical The operators should be responsible people trained in basic laboratory protocol and they should be familiar with the possible hazards before operating this instrument All instrument modifications should be performed only by personnel trained by GE Healthcare Equipment damage personal injury or even death may result if this equipment is operated altered or maintained by untrained personnel or in an irresponsible or improper manner 2 1 Safety precautions Introduction Before installing operating or maintaining the system you must be aware of the hazards described in the user documentation Follow the instructions provided to avoid personal injury or damage to the equipment The safety precautions in this section are grouped into the following categories e General precautions e Flammable liquids e Personal protection e Installing and moving the instrument e System operation e Maintenance MicroCal VP ITC Operating Instructions 28 9639 79 AA 15 2 21 Safety instructions Safety precautions General precautions WARNING Provide proper electrical power to the instrument Thi
64. uide sleeve into the pipette and secure it with the threaded cap as shown above 2 Click on the Remove Old Tip button within the Setup Maintenance tab The tip will move to a location where it is easy to remove 3 Insert the tip puller tool through the center of the guide sleeve and over the plunger tip pull it back out It should grab the plunger tip and pull it off If it does not use the manual position controls in the Setup Maintenance tab to lower the tip 2 3 mm and try again 4 Click the Install New Tip button to move the plunger to a convenient location for inserting a new tip MicroCal VP ITC Operating Instructions 28 9639 79 AA Maintenance 5 Syringe height adjustment 5 5 5 Place anew tip in the tip pusher tool with the hole up Slide the tip pusher into the guide sleeve and gently but firmly onto the end of the plunger Remove the tip pusher The new tip should be securely seated on the plunger After a tip is replaced it will need to be polished to ensure a tight seal with no tip irregularities 6 Click on the Polish New Tip button The injector screw should extend out several centimeters and be hidden by the guide sleeve This makes it easy to polish the tip without bending the injector screw 7 Carefully push the glass bore polishing tool over the new plunger tip Push it back and forth over the plunger tip 30 50 times it should move more easily as the tip becomes more polished 8 Click on the New Tip Polished button
65. where bubbles may rest 8 34 Finally lift the tip of the syringe to the cell port just below the visible portion of the cell port and find the ledge See Figure 4 2 that is formed where the cell stem MicroCal VP ITC Operating Instructions 28 9639 79 AA Operation 4 Basics of performing a run 4 2 meets the cell port Place the syringe on the ledge at the top of the metal cell stem and remove the excess solution Figure 4 2 Cell stem ledge B Ledge formed where the cell tube meets the plastic filling port If the reference cell needs refilling follow the same procedure as for the sample cell Note There is no need to refill the ITC reference cell after each experiment If the water was thoroughly degassed before filling it may be good for a week or two with no attention NOTICE If the reservoir overflows during the filling procedure the fluid may contaminate the stir motor bearing and damage it beyond repair Care should be taken not to overfill the reservoir If an overflow does occur the injector should be removed and the bearings on the underside should be wiped dry If internal contamination is suspected please consult with GE Healthcare personnel for further recommendations Pipette filling 1 Degas the titrant for 5 minutes and place in the pipette filling tube 2 Place the pipette filling tube into the bottom of the stand see Figure 4 3 3 Carefully insert the pipette into the pipette sta
66. xperiment s data file itc the run parameters are extracted from the data file header or a setup file inj which was previously saved using the Save Run File button Save Run File displays the file save dialog box which allows saving of the currently displayed run parameters Once the parameters have been saved they may be reloaded and reused in the future by selecting Load Run File as described above Display Run Parameters displays the current run parameters for the run in progress This button is available only when the MicroCal VP ITC is in a non idle state Update Run Parameters updates the current run parameters for the run in progress When the ITC is in a non idle state this button must be clicked for the run parameter changes to take effect This button is available only when the MicroCal VP ITC is in a non idle state MicroCal VP ITC Operating Instructions 28 9639 79 AA Operation 4 Basic VPViewer controls 4 3 Note Only run parameters that have not yet been applied on the run in progress may be updated all others will be ignored i e after the stirring has commenced for an experiment changes to the experimental stir speed will be ignored The Total Injections 500 is the maximum sets the number of injections for the titration ITC experiment The multiple injection method requires a minimum of 10 15 injections There are no negative consequences except the time spent to titrating past the point where all sites

MicroCal™ VP-ITC System - Chemical Instrumentation Facility

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MicroCal&trade; VP-ITC System - Chemical Instrumentation Facility

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MicroCal™ VP-ITC System - Chemical Instrumentation Facility