I IP'd biotynylated protein with avidin beads. I washed the beads and eluted in Laemmli buffer +DTT. I heated to 95 C for 10 minutes. I then froze to samples at -80 to run a few days later. Is it OK to heat the proteins and run the samples on SDS Page gel? Would it have been better to have kept it at 4 C? I know precipiatation of the protein is a concern, but so is degradation. Since the reduction with DTT is not permanent, is it necessary to add addioional DTT?