An investigation of the factors controlling the staining and destaining of electrophoresis gels.

A general analysis is developed for the effect of mass transport and kinetic parameters on the rate of staining and destaining of electrophoresis gels. The various contributions to these overall processes are discussed and, in particular, the ways in which the rate of solution flow, temperature and gel properties can influence staining procedures are highlighted. It is shown that for reproducible, rapid and uniform staining a rotating gel system, analogous to a rotating disc, provides the necessary controlled laminar flow. The theoretical equations derived are compared with experiments and it is shown that at high gel rotation speeds mass transport in solution does not have a major controlling influence on rates of staining and destaining. The temperature dependence of these rates also suggests that there is no significant control by the rate of interaction between stain and protein molecules. The major controlling factor under these conditions is then concluded to be the transport of stain in the gel itself, and the theoretical analysis and time-dependent experimental results allow a determination of the corresponding diffusion parameters.