Direct tissue isoelectric focusing of nervous system and muscle sections for detection of IgG patterns.

Agarose isoelectric focusing (IF) of 5-70 microns sections of frozen autopsy material (direct tissue IF; DTIF) from the central nervous system (CNS) and peripheral nervous system (PNS), and from muscle biopsy, followed by immunofixation with unlabeled or radiolabeled anti-serum against human gamma chains or IgG Fc fragments has been developed for analysis of IgG patterns. The DTIF technique followed by antiserum immunofixation is a promising tool for characterization of proteins in autopsy and biopsy materials from nervous and muscular systems. In multiple sclerosis brains, oligoclonal IgG bands were found which differed regarding number and mobility between the brains, and also between two different regions in single brains. For PNS, IgG patterns were easily detectable. In polymyositis muscle, no difference was found for IgG patterns when compared with normal muscle or serum.