A sensitive and reproducible method for the detection of oligoclonal IgM bands

We have developed a sensitive and specific isoclectrofocusing (IEF) method for the detection of oligoclonal (OGC) IgM in the cerebrospinal fluid (CSF) and sera. In this procedure, ampholytes, in the range pH 5-8, were used to improve the resolution, and serum was diluted in saline to avoid IgM precipitation. Samples were treated with 50 MM dithiothreitol (DTT) at pH 9.5 to reduce lgM and improve the migration of the protein. Using an anti-IgM labelled with alkaline phosphatase, the limit of detection was found to be 0.1 ng in 5 mul of sample. (C) 2001 Elsevier Science B.V. All rights reserved.