Note from moderators: the following query was posted in response to another forum thread. We have re-posted it here to increase its visibility.

Hallo,
I have a small question about the imidazole/zinc sulfate dye of 2D-SDS-PAGE gels.
I am trying to do that and according to a pubblication (Castellanos, 1995)I have read that it is possible to do it in double staining (Coomassie-imidaz/ZincSulfate)…I have used Coomassie stained gels and unfortunately with the reverse staining I could detect only the bands corresponding to Coomassie (the look trasparent of course) but actually nothing more….I have followed the procedure as they have described….maybe have I to de-stain the Coomassie gels, before the negative staining to see even the negative proteins?
Thanks in advance for your help :)