I try to perform co-immunoprecipitation with cell culture supernatant as my two proteins of interest are secreted. I've read suggestions for IPs with cell media. One is to concentrate the media via centrifugation filters. Is that also applicable for co-IPs? Does the centrifugation interfer with the interaction of my proteins? Are there other more sensitive concentration methods? Another problem is that one of the proteins is rather unstable and is a protease. Well, actually that's two more problems...
Any suggestions? I'm thankful for any advice.
Thanks!













