Comparison of polyacrylamide and agarose support media for detection of oligoclonal IgG bands in CSF

Abstract

Parallel samples of cerebrospinal fluid (CSF) from 120 patients clinically suspected of having multiple sclerosis were electrophoresed using agarose or 7% polyacrylamide. 57 samples showed oligoclonal IgG patterns in polyacrylamide but only 34 showed bands after concentration and electrophoresis in agarose. The concentrations of IgG and albumin were also measured in each sample and IgG/albumin ratios calculated. The sensitivities of the three methods for the detection of intrathecally synthesised IgG were compared. Electrophoresis in 7% polyacrylamide gave the highest proportion of significant results. In an attempt to increase the sensitivity of the agarose method, silver staining was performed on unconcentrated samples run in agarose. This did not alter the pattern of electrophoresis in samples containing oligoclonal IgG, but the sensitivity of the technique was lower than that of polyacrylamide.