Protein Bands Run to Bottom of Gel

[IoDiNE]

Hi everyone I have a weird problem with my SDS gels lately.

I froze my samples and ran them on the gel, however all of the proteins run down to the bottom of the gel....

I checked my buffers the pH and the sample buffer/loading buffers are correct...

I have no idea what can be the reason?

Has anyone had any experiences like this?

thank you for your advices

[aftabac]

well
sometime when you repeatidly freez thaw your protein samples then it get degraded, so try to avoid this. but if you just freez it once then no problem, but it is better that you prepare your samples and immediatly use it.
secondly i think there is problem in the gel and there is possibility that the pore size of the gel was large so all the protein move down, so prepare once again your gel with defined concentration according to your application and run your samples once again, hopefully you will find out your problem

best of luck for experiment.

regards
aftab

[trypsin]

Many people use 10% sds-gels for seperating proteins but it isn't good for small proteins. Gels which have 15-18% acrylamide are better. And for very small proteins you should try to use the tris-tricine (from schaegger and jagow) instead tris-glycine buffer system. But at first you should try to seperate your proteins with 15 % gels.
good luck. trypsin