Abstract
Human anti‐S and anti‐s eluates bound to glycophorin B on immunoblots from membranes of S+ and s+ red cells, respectively. Eluates of human anti‐S were more efficiently prepared from sensitized trypsin‐treated cells than from sensitized untreated cells. The results of immunoblotting membranes from enzyme‐treated cells confirmed the serological findings: S and s antigens were not affected by treatment with trypsin or sialidase but were destroyed or much depressed by treatment with papain, pronase or α‐chymotrypsin. Immunoblotting with anti‐S or anti‐s of membranes from cells with unusual MNS phenotypes confirms the involvement of glycophorin B in hybrid glycophorins; the existence of such hybrid glycophorins was deduced previously from serological work or immunoblotting with monoclonal antibodies. The presence of s‐active glycophorin B in glycophorin (B‐A)Dantu, in glycophorin BMiIII and in glycophorin (A‐B)MIV was confirmed. The bands observed when Mit+ membranes were immunoblotted with anti‐S supports the suggestion from serological work that the Mit antigen is associated with an altered S antigen.