Differences in Antigenic Specificity of Human Normal Adult, Fetal, and Sickle Cell Anemia Hemoglobin

By MORRIS GOODMAN, PH.D.* AND DAN H. CAMPBELL, Pn.D. T HE DEMONSTRATION by Pauling et al.’ that sickle cell anemia hemoglobin has a slightly higher isoelectric point (0.2 pH unit) than normal human adult hemoglobin and the reports of differences in ability to form nematic liquid crystals2 and solubility differences in strong salt solutions3 suggest that differences might also exist in immunochemical properties. Differences between antigenic specificity of fetal and normal adult hemoglobin have been reported by Darrow et al.4 Vecchio and Barbagello5 confirmed these findings and also concluded that sickle cell anemia hemoglobin had the same specificity as normal adult hemoglobin. Unfortunately these two studies were carried out by means of the precipitin ring test so that it seemed desirable to repeat the study using more quantitative methods. Two sets of experiments were undertaken. The first, rather preliminary results indicated that normal adult and sickle cell anemia hemoglobin differ in their serologic behavior but that this could be explained on the basis of differences in physicochemical properties rather than antigenic specificity. The second series