Finding suitable Acrylamide/Bis-acrylamide ratio (View forum version)

Meg P. Anula

Posted 16 September 2015 - 10:59 PM

Hi guys,


I will be doing protein expression work and will need to run SDS soon.


Right now I am working on a 27 kDa protein and soon my work will be on a 63kDa protein.


But I am confused to which ratio of acrylamide/Bis-acrylamide premixed solution (Biorad) to buy.


How do I know which ratio is suitable for my protein? 




Posted 17 September 2015 - 05:17 AM

These sound like very typical protein sizes, so a normal 19:1 ratio would probably work well.


Posted 18 September 2015 - 05:11 AM

i've always found that 37.5:1 is pretty standard for protein page although thermo-fisher seems to recommend 19:1.


however, i think you are also asking what should be the total acrylamide concentration for the gel. assuming that you are only interested in the 2 sizes you give, you can probably use a 10 or 12% gel.


see this chart for tris-glycine sds-page gels from thermo-fisher.