User`s manual

64 Chapter 6: Sample Experiments
Calorimetry Sciences Corp.
CSC 5300 N-ITC III 65
User’s Manual
The presence of bubbles in the solutions can result in noisy baselines or spikes during
an experiment. It is therefore necessary to remove dissolved gasses from the solutions.
Sample degassing is most important for experiments being run at or above ambient
temperature since gasses become less soluble with increasing temperature. Degassing
is more efcient if the solution is being stirred, but stirring may not be practical for
small volumes of solution. Degas 2 to 3 mL of 2’-CMP solution as above, and allow the
solution to return to ambient temperature.
Experiment Setup
Experiment parameters:
Equilibration time 200 s
Time between injections 200 s
Injection size 5 μL
Number of injections 20
Rinse the calorimeter cell three times with buffer solution and then load the sample cell
with degassed RNase A solution. The reference cell may be lled with degassed water.
Allow the cells to thermally equilibrate until the heat reading on the calorimeter is stable.
Load the 100 μL syringe with the 1.3 mM 2’-CMP solution, making sure to remove any
bubbles from the syringe. Wipe the needle with a tissue and then screw the syringe com-
pletely into the burette drive. (Note: Before inserting the syringe into the burette drive,
verify that the plunger indicator on the graduated handle is in the fully raised position.
Otherwise, mount the burette on the N-ITC III without a syringe and click the burette up
icon to initialize the plunger position.) Insert the syringe and burette drive into the N-ITC
III.
Turn on the stirrer at 150 rpm, allow the system to re-equilibrate until the heat reading on
the calorimeter is stable, and then begin the experiment. Enter a le name for the data at
the prompt.