Protein Smearing - (Mar/23/2010 )

I'm using a 15% gel in a tris-glycine-SDS-PAGE system and I've extracted protein from live tissue but I seem to be getting no clear bands at all and just a smear. Even the markers don't appear crisp/clear. I've tried using a gel stain to visualize any protein following electrophoresis and it looks the same was as it does when i expose from the PVDF membrane.

Current parameters:
Run Time ~ 3 hours
Voltage - 90Volts
The protein i'm looking for is approximately 20 kda

Any help would be greatly appreciated

-Dk-

looks like a degraded protein sample. Did you add protease inhibitors when preparing the tissue lysate?

Check the pH and salt content of your buffers, especially the ones used for making the gels.