A simple method for the production of F(ab')2 preparations by pepsin digestion of total serum protein.

An easy and rapid method for producing F(ab')2 fragments by pepsin treatment of total serum protein is described. No further purification of the hydrolysate was used. Most serum proteins were degraded to small peptides which were removed by dialysis, the preparations thus being relatively rich in F(ab')2 fragments. The degree of hydrolysis was determined by means of an antiserum against the part of the gamma-chain which is degraded by pepsin. Under optimal conditions for hydrolysis, unsplit IgG could not be detected by double immunodiffusion. Using sperm-agglutinating and immobilizing sera, the F(ab')2 preparations could be characterized functionally. After hydrolysis the agglutinating activity was relatively unchanged, whereas the immobilizing activity had vanished.