In Isothermal Titration calorimetry experiment shows kind of oscillatory heat signal i.e, each injection shows both exo and endothermic peak even for heat of dilution experiment. This oscillation keeps on increasing with the number of injections. Can anyone please tell me what could be the reason for this. (ITC cell contains protein solution, syringe contains just buffer)
there may be many reason-
1. Washing is not proper, trace amount of methanol is still there in syringe. so after washing, dry syringe properly.
2. May be your sample cell filling is not proper. there might be air bubble, those bubbles creates fluctuation in base line.
3. your buffer composition is not same for sample cell and syringe?
Hi, another aspect is that the buffers used for protein dissolution and blanks need. to be identical. There may be heat release/absorption due to possible reactions between the protein and the added buffer (if buffers are slightly different). There is also a 'gain' parameter in the regulation of thermal equilibrium between reference and tritration cell that may be not optimal, and could be a source of oscillations. You would probably need to check the manual or ask for furhter expert advice concerning the type of ITC you work with. Good luck. -pr
Thanks Peter, Jose and Ajeet for all your valuable answers and suggestions.
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