making a master mix for SDS-PAGE

tfitzwater at tfitzwater at
Wed Nov 8 16:52:53 EST 2000

>Michael L. Sullivan (mlsulliv at
>Tue 07 Nov 2000 - 15:27:02 GMT>Since I mostly run 10% SDS-PAGE gels, is
there any reason I can't make up a
>master mix of acrylamide, water, SDS, and buffer that would need only to
>have APS and TEMED added?

>I know that such mixes are available commercially, but I wasn't sure
>whether those might have some additive that would prevent some dire
>consequence of mixing the other components for longer term storage and

>Thanks for any insight.

>Michael L. Sullivan, Ph.D

We routinely prepare denaturing acrylamide mixes from commercial liquid
acrylamide:bis stocks, TBE and urea.  The urea is dissolved by briefly
microwaving the mixture.  We do not filter the stock solution in case the
liquid stocks contain that rumored gaseous stabilizer.  At Boulder's
altitude (1 mile), degassing of acrylamide stocks is not necessary (if
there is reduced dissolved oxygen, there is probably not a lot of
stabilizer either).  Stock is stored in polystyrene bottles on the benchtop
without foil wrapping for 2 months.  At about 2 months, the polymerized
gels suddenly develop a UV shadow that tells us that it is time to prepare
a fresh stock.  Nucleic acids eluted from the heavily shadowed gel behave
normally.  Have not tried this with SDS, but expect that it will work.

Tim Fitzwater

Principal Research Associate

Gilead Sciences


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