Identification of Abnormal Hemoglobins : V. Detection and Identification of Unstable Hemoglobins

An over-all discussion on authors' experience in the detection and identification of 15 unstable hemoglobins causing hemolytic disease and 6 slightly unstable, clinically harmless variants is presented. The diagnostic efficiency of routine screening procedures including erythrocyte oxygen equilibrium curve, glycerol lysis time, starch gel electrophoresis of hemolysate, levels of Hb A_2 and Hb F, qualitative heat precipitation and isopropanol tests was compared with that ot quantitative proccdure of heat denaturation, PCMB (p-chloromercuribenzoic acid) precipitation, mechanical shaking and Sephadex G-75 gel filtration. Urea polyacrylamide gel electrophoresis of the PCMB precipitate was superior to the other methods as a method of detection of unstable hemoglobins and identification of chain anomaly. The PCMB precipitate proved to be a satisfactory starting material for the purification of the abnormal globin by urea CM-cellulose column chromatography. A systematic approarch to the laboratory diagnosis of unstable hemoglobin hemolytic disease was proposed.