“…Two possible modes of action are advanced to explain this observation: 1. the proteolytic property of the enzyme removes material from the surface of the red cell, thus exposing additional antigen [16,18,20], and 2. the enzyme modifies the ionic strength at the site of reaction between the red cell and antibody and leads to increased binding of antibody [8,15,19]. Hughes-Jones et al [12,13] have shown that the treatment of erythrocytes with ficin causes an increase in the value of the equi librium constant as a result of more rapid union of antigen and anti body.…”