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question about SDS-PAGE - electrophoresis of proteins (Jul/29/2004 )

I need to do some electrophoresis of proteins. I have experience of nucleic acid electrophoresis, but have no experience about proteins. In some handbook I found that there are at least two types of SDS-PAGE of proteins, Tris-tricine buffer system (discontinuous) and continuous system. The latter seems to be simple, but I encountered several problems. The 4* phosphate/SDS buffer (0.4 M sodium phosphate/0.4% SDS, pH 7.2) is said to be able to be stored at 4C degree for up to 3 months, but in my hand the buffer crystallized after being put into the refrigerator (4C degree). Even under room temperature there are some crystals. And same thing happens with the 2*phosphate/SDS sample buffer (20 mM sodium phosphate, 2% SDS, 0.001% bromophenol blue, 0.2 M DTT, and 2% glycerol). I don't know whether I need to store these buffers under room temperature. Any suggestions would be really appreciated. Thanks a lot.


Email me and i will send u the protocol i use to run 8-12% Polyacrylamide Gels as well as making sample buffer and the appropriate solutions. The SB i use i store in the -20 freezer in aliqouts, then i take one out at a time and thaw at 37oC. Vortex ur SB and thaw it takes a while for it to dissolve. Once it took me 20min holding the tube on and off the vortex machine to dissolve it. my email is



I think you freezer has some problem. But in my case,I just put the buffer at room temerature. It works well with in two month. Do not be worry about it.
Good luck!


By the way, you can resolve the buffer at room temperature when it crystal.


hi ,
make sure that u store ur sample dye at 25^C (RT) ,to avoid crystalization don't store at 2 to 8 ^C (refrigerator).
can i expect ur SDS-PAGE protocol.
see u

-rajani kanth-