2 replies to this topic

[buzzking00]

I have an Invitrogen Xcell SureLock mini cell for gel electrophoresis.
As far as SDS-PAGE gels, I would use a higher % gel for lower M.W. protein.
My boss asked me what percent gel I should use for Fab and F(ab')2.
I suggested 18% for Fab and 12% for F(ab')2 for a SDS-PAGE gel.
He says it is not quite correct.

I am thinking it is because he is looking to use a native urea gel [he asked when I would use a urea gel and if I knew what a native gel was right before he asked what % gel I would use for Fab and F(ab')2].
What % native urea gel should I use and why?
If you could link the Invitrogen gel cassette for the gel you are referring to, that will be helpful as well.

Edited by buzzking00, 09 July 2012 - 03:34 PM.

[mdfenko]

urea enhances charge separation of otherwise equal proteins (the more negatively charged protein will migrate farther).

technically, urea-page is not native (urea does disrupt protein conformation) but you add urea to native page (similar to adding sds to native page).

we used a 7.5% acrylamide gel to separate phosphorylated from non-phosphorylated 20kDa proteins and 3.5% (i think, may have been 5%, sorry, it was a long time ago) for 200kDa.

[buzzking00]

Thank you for your prompt response.

Does anyone else have more information to add to this topic ?