Evans blue as counterstain in the demonstration of muscle antibodies by immunofluorescence in myasthenia gravis

Abstract

The binding of muscle antibodies to skeletal muscle was studied by immunofluorescence techniques. The nonspecific fluorescence was not significantly reduced by absorption of the conjugate by tissue powder but was abolished by counterstaining with a 0.1% Evans blue. Possible explanations for this effect are discussed. By this method, immunofluorescence may become more useful in the demonstration of muscle antibodies.