Im working on GLUT-4 levels in baboon muscle, and I am using alpha-tubulin to normalise. I am getting two bands though, one strong band at about 100kda and the usual (less strong) 55kda that I am expecting. I am aware that alpha + beta tubulin is at roughly 100 kda. What possible reason could there be for two bands to consistently appear, even when the dilutions were checked and rechecked? I dont think it is a blocking problem, as these two bands appear regardless of blocking bsa or milk for long periods. Any help would be much appreciated.