Cerebrospinal fluid (CSF) specimens from 45 clinically definite MS patients were studied for the presence of oligoclonal IgG bands by sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The protein bands were identified by Coomassie blue (CB) dye and silver staining. Thirteen patients showed no bands in their CSF by the CB method. Nine of these 13 patients showed presence of bands by silver staining alone. Thirty-two patients showed more than two bands in their CSF by either technique, and 28 of the 32 patients showed from one to five additional bands by silver staining compared to Coomassie blue staining. The silver staining method was thus more sensitive in identification of oligoclonal bands in CSF.