I have a question about protein precipitation. I precipitate my proteins with methanol and chloroform. The final step is that I wash my pellets with methanol (1ml). Because of the fragility of the pellet I put it in all in the speed vac and dry the pellet. What could happen with the proteins when I overdry the pellet. After drying I resuspend the pellet with 2x sample buffer. When I loaded the protein on the SDS-PAGE I observed that in the bottom of the tube a residue is visible. Something viscous or the like. Is this the overdried pellet and the proof that not everything was properly resuspended?
Thanks for all comments.