Low MW peptide detection on SDS PAGE

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Aryae
Aryae's picture
Low MW peptide detection on SDS PAGE

Hi everybody, I have problem to detect 2KDa oligopetide on SDS PAGE. I made 17% Tris-Glycine gel and stained with CBB but didn't work as usual. Anybody does have a protocol for low MW peptide? I' going to do western blot on this SDS PAGE. I heard about Tricine gel but don't have all stuff and no money to buy them. Thanks in advance

g a
g a's picture
 Hi Aryae

 Hi Aryae

You can increase the %  of cross linker in the regular 17% gel. In addition increase the pH of yr resolving gel to 9.5  as compared to yr regular8.8.
Dont have the exact protocols but both these worked well for me.

All the best

Sami Tuomivaara
Sami Tuomivaara's picture
Aryae,

Aryae,

You should remember that small peptide binds less CBB than larger one, thus smaller peptides are harder to detect. If you really want to see your peptide on the gel, you can try to load more (or try other detection method). Changing the gel % won't help you here, unless you think your peptide migrated out of the gel.

If you are going to use western anyway (which is way more sensitive detection method) why bother with the gel staining?

Cheers,