Glutaraldehyde-enhanced immunofixation: a sensitive new method for detecting oligoclonal immunoglobulin M

A new, specific and economical method with enhanced sensitivity for rapid detection of IgM oligoclonal bands in unconcentrated cerebrospinal fluid (CSF) is presented. It is based on the use of glutaraldehyde during immunofixation of electrophoresed specimens and utilizes peroxidase-conjugated F(ab')2 fragment of anti-IgM antibody to avoid cross-reactivity with other CSF gamma globulins. It is able to detect 1 ng of IgM banded protein in electrophoresed CSF. Using this method, oligoclonal IgM was mainly detected in inflammatory and infectious conditions of the central nervous system.