The size of the fibre populations in rabbit skeletal muscles as revealed by indirect immunofluorescence with anti-myosin sera.

Antibodies against myosin of the fast long. Dorsi and the slow soleus muscle of rabbits were induced in guinea pigs. With the aid of a new technique, the gel-electrophoresis-derived-enzyme-linked-immunosorbent assay (GEDELISA) it could be shown that they are directed against the heavy and the light chains of fast (M. long. dorsi) and slow (M. soleus) myosin. In the indirect immunofluorescence test each antiserum only stained one population of fibres in five different muscles tested. The single fibres were observed to react only with one of the two types of antisera. The following percentage of fibres showed a positive reaction with the anti-fast myosin serum: M. long. dorsi, 95%; M. psoa maior, 95%, M. psoa minor, 92%; M. tibialis ant., 90%; M. soleus, 15%.