Does anyone know why streaky bands appear on SDS-PAGE for Western Blot?

I am doing western blot with brain protein samples. I loaded replicates of 5 samples in 4-12% Bis Tris gel and cut it in half. I found that sample 2 and 3 are streaky at replicate #1, but sample 2...

24 October 2014 3,668 3 View