Beta alanine alternative? - (Mar/08/2013 )
Hi I also need the appropriate resolving and stacking gel compositions for different percents 12% and 15%.thank you.
beta-alanine is a beta amino acid, l-alanine is an alpha amino acid (position of amine relative to carboxylic acid group). you can look at the wikipedia page about beta-alanine.
to replace beta-alanine in the running buffer, you must find a buffer with a similar pK that won't otherwise react with the samples. malic acid may fit the bill, but you should check buffer tables.
as for tracking dye, you could use bromphenol blue if you don't mind looking for a yellow band (i think it actually remains blue at the running pH of 4.3).
the stacking gel formulation (2.5% acrylamide, 0.625% bis-acrylamide) should not be adjusted for different percentage separating gels.
the recipe i have (and think have posted someplace on bioforum) makes a 15% separating gel. just adjust the acrylamide and water to make 12% (reduce acrylamide volume by 1/5th and increase water by the difference in acrylamide volume)