I would greatly appreciate any advice on preparing tissue for western blot with human postmortem tissue. I can get bands for my proteins, but they are variable and it seems to be most variable at the upper molecular weights (membrane bound proteins) and not the lower molecular weight soluble proteins so I think it is a solubilization issue. I have tried RIPA and RIPA with urea (although urea prevents me from using an enzyme I need) with sonication and got similar results. I also tried 2% SDS in tris buffer and boiling, but it made my proteins precipitate and not migrate into the gel. Does anyone have tips for solubilizing membrane proteins from human tissue? Thanks!