Silver staining of cerebrospinal fluid IgG in isoelectric focusing gels

A silver staining technique to be used on isoelectric focusing (IEF) gels for cerebrospinal fluid (CSF) oligoclonal IgG bands is described. The technique provides a sensitivity for detection of greater than 0.17 micrograms of IgG. The additional use of immunofixation with anti-human IgG antiserum rather than chemical fixation improves the sensitivity two-fold and permits identification of the oligoclonal bands as IgG. The technique enables one to focus small volumes of unconcentrated CSF (less than 40 microliters) and provides a powerful research tool.