Is there any different results between 150mM NaCl and 75mM NaCl lysis buffer if i do a co-IP?
I want to find the interaction between my interest protein and the other eight proteins.Last week,i did a co-IP.However,the lysis buffer i used was 75mM NaCl and the result was that my interest protein interacted with four proteins.Will it be the same result if i do a co-IP using 150mM NaCl lysis buffer?
Probably you will get the same result with 75 or 150 mM. If you want to test the influence of the salt concentration on the interaction, you should include higher concentrations, like 0.5 M and 1 M NaCl.
Hi Zang,
if the interaction among your proteins of interest is expected to be mainly ionic, the salt concentration may have a great influence on the outcome of your experiment.
As first attempt, I suggest you to use a salt concentration as close as possible to the physiological conditions (I mean, the concentration of salt that is present in the natural environment of the protein, where the interaction is supposed to happen).
If this information is not available, I would certainly follow the suggestion of Konrad, and preform the experiment at different salt concentrations. This is a quick way to get an idea about the "strength" of the interaction, and helps in understanding if the result is meaningful or not (interactions observed only at very low salt concentration often are false positives).
Hope to have been helpful...Good luck with your experiments!
- Badges
- Science method