Antiglobulin factors in normal mouse serum reacting with enzyme-digested gamma globulin

The presence of antiglobulin factors in normal mouse serum was studied. Mice were injected with human 0 Rh(+) erythrocytes and the resulting gamma globulins were digested with papain. The reaction was demonstrated by agglutinations of human 0 Rh (+) perythryocytes sensitized with the Fab fragments when treated with normal mouse serum. Studies suggested that there are two factors in mice, a 7S AND A 19S globulin form. Cross-reactivity between strains of mice was demonstrated.