Hi !

Out of curiosity, I recently tried to cast an acrylamide gel with 2 concentration of separating gel (15% down and 7.5% up) to try and visualize purified proteins of 30 kDa at the same time as 150 kDa protein.

(I know this is not a proper way to get a definitive result but it can come in useful for an intermediate backgroud check in IP before proceeding any further with my preliminary experimentations... And now that I have notice a problem, I am curious about what appens electrically in the gel)

I could visualize the proteins all right, but the migration was ultra-long, due to a lot of security interruption by the power generator which detected brutal changes in resistance all the time. This was more obvious with higher voltages than with the low ones, but eventually occurred even at low voltages (1/4 of my usual migration voltage of 150V which never caused me any trouble before).

Hence, my question : what is known on the electrical impact of the interference between 2 different acrylamide concentration within a gel ?

Is there anything known on that matter about the interface between staking and resolution gel ?

I tried to look in different places for this troubleshooting but didn't find anything relevant to this issue.

In advance, thank you so much for your help :)

Gweltaz