The A, M, N, and P1 blood group substances in butanol extracts of human erythrocytes.

Aqueous phase and butanol phase extracts of group A1, O, M, N, P1 and P2 human erythrocytes perpared by extraction of red cell stromata with n-butanol were examined for the presence of blood group substances in inhibition of agglutination experiments using antisera and test cells of human origin. Group A substance was recovered in both aqueous phase and butanol phase extracts, M and N substance in aqueous phase extracts only, and P1 substance only in butanol phase extracts. Use of high concentrations of extract resulted in detection of P1 activity in aqueous phase extracts and of N specific inhibition in the aqueous phase extracts of group M erythrocytes. Distilled water appeared to be superior to digitonin and hypotonic phosphate buffer solutions for preparation of stromata for the recovery of group A and M substances in the butanol extracts but not for group N and P1 substances.