I would like to know if someone could give me a protocol to coat collagen IV (stored in 0.5M acetic acid) on a polycarbonate filter to set on a 12-well chemotaxis chamber (neurobrobe). The problem is that I would like just to coat the regions of the wells and that I want to get rid of the acetic acid...

hi,
i m afraid that i did not get exactly what you are asking. generally i too use collegen in aqueous solution and dry the membrane before use for migration.
when you coat your polycarbonate membrane with the mentioned collagen in 0.5M acetic acid, you will dry the membrane before use it for migration so when you will find the question of acetic acid presence?

let me know if you need any clarification

gud luck