FLAG Peptide how much to use w/M2 clone - competition w/M2 clone for immunocyto (Sep/14/2005 )

Does anyone have any specific knowledge regarding the use of the FLAG peptide from Sigma for use in peptide blocking experiments for immunocytochemistry with the M2 clone FLAG mAb. I know the general rule of excess peptide to antibody. Looking for people that have first hand knowledge of using this peptide.

I can remember reading a paper where they did sequential Immunoprecipitations of a FLAG fusion protein, one with an Ab for the FLAG epitope and one with an Ab for the actual protein. In between IP's they used 100 ug/mL FLAG epitope to elute the antigens for the next step of IP.

This concentration seems a bit high to me but at least it may be a starting point that is validated.

Good Luck