APS & TEMED in acid gels

[The Great American Gene Company]

In <5c5r41$rrt at light.nih.gov> bernard at elsie.nci.nih.gov (Bernard
Murray) writes: 
>
>In article <1997Jan22.123448.9875 at news.iup.edu>, jford at grove.iup.edu
says...
>>
>>If you can the amounts of APS and TEMED, you will change the kinetics
of 
>>gelation (great, that's what you want).
>
>Agreed.  You can also control kinetics by changing the temperature.
>
>>  You will also change the porosity of 
>>the gel - the relative amount of cross-linking.
>
>Is this really true?  I was under the impression that the porosity
>was governed by the % acrylamide and by the ratio of acrylamide/bis
>(or other cross-linker).  The concentration of TEMED and/or
persulphate
>shouldn't have any effect unless they become limiting - so that the
>gel fails to polymerise completely no matter how long it is left.
>Since they only catalyse the polymerisation of the acrylamide monomer
>they play no real role in the eventual structure of the gel.
>	Can someone correct or confirm my assumption?
>		Bernard
>
>Bernard Murray, Ph.D.
>bernard at elsie.nci.nih.gov (National Cancer Institute, NIH, Bethesda
MD, USA)
>

Dear Bernard:

It is most definitely true.  There is a literature (albeit somewhat
obscure) on the subject.  I can give you one reference:

MacDonell, M.T. et al. 1993. Minimization of pore diameter in
polyacrylamide by crosslinker concentration is temperature dependent.
Mol. Biol. (Life Sci Adv.) 12:47-48

Send me a fax number and I will fax it to you!

-Mike
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