The I, i, and HI blood group antigens in extracts of human erythrocytes.

Extracts of stromata of human adult and newborn (cord) erythrocytes were prepared with n-butanol. The aqueous phase and butanol phase extracts were examined for the presence of blood group I, i, HI and H substances in inhibition of agglutination experiments. The recovery of HI activity in both the aqueous and butanol phase extracts of adult red cells but only in the aqueous phase of cord cells is reported heare for the first time. The i specificity was present in the aqueous phase but not in the butanol phase of cord erythrocytes, also not previously reported. Although the recovery of I but not i substance in aqueous phase extracts of adult cells had been shown by other workers, examination of the butanol phase extracts for I and i substances had not been documented. In the present study, Ii substances were not demonstrable in any of the butanol phase extracts of adult and cord erythrocytes.