SUMMARY A method of studying protein binding of muscle relaxants, using an electrophoretic technique to separate protein fractions, is described. Results are presented for three tritium labelled muscle relaxants: dimethyltubocurarine, gallamine and decamethonium. Differences were shown in both the binding patterns of the drugs and in the absolute amounts bound. Dimethyltubocurarine was bound most by gamma globulin whereas the other relaxants were attached mainly to the beta globulin fraction
