Saving lysate with laemmli in -20? - (Mar/26/2011 )

Question. I had to run a gel, but it was getting kind of late, and I already added the 5x laemmli to some samples, so I just put it in the minus 20. It doesn't seem like that big of a deal, but if I were to take a lysate or any sample for an SDS PAGE and add the proper amount of 5x laemmli buffer with BME and everything and just save it overnight in the minus 20, would it be okay? It doesn't seem like it should be a problem to just boil it and load it to run a gel the next day. I'm just wondering if anyone can tell me if they've done this and ever run into a problem.

It should be fine, especially if you have protease inhibitors in the lysis buffer.

kmh on Sun Mar 27 01:04:12 2011 said:

My boss actually prefers that I save my proteins this way so that it is quicker to replicate and to prevent the protein from aggregating or absorbing to the tube and what not. The only thing that I've found is that if you freeze/thaw/boil several times the samples will begin to be degraded.

I have left serum samples in laemmli at 4C up to 5 days before running them on a gel and had a perfectly good looking gel.

when you thaw, make sure that the sds is back in solution. otherwise there is no problem freezing the samples.

did you boil the samples before freezing? if so, then you don't have to reboil.

Thanks for all the helpful responses! I was just worried if there was something important I was overlooking when I saved my samples. The gel and the western worked out pretty well though. I have to run one again tomorrow, so I might as well save some time today.