Isoelectrofocusing: a method of multiple applications for hemoglobin studies.

A microanalytical screening of hemoglobins by isoelectric focusing on acryl-amide gel columns is described. Addition of this technique to our regular analytical procedures revealed many mutants, praticularly some neutral ones which were not resolved by other conventional procedures. Extension of this technique to a quantitative scale permitted rapid isolation of some unstable mutants in an almost pure form ready for functional studies. The natural color of the separated components is often indicative of their nature and in cases like the sulfhemoglobin, Hbs M, they are of diagnostic value. The heme-losing, abnormal, unstable mutants, on the addition of external cyanhemin, take them up and change their isoelectric pH. This is an attractive visible procedure for their diagnosis. From all these results, it appears that isoelectric focusing as a single method brings more information than the other conventional procedures and hence can be considered as a semi-routine investigation for hemoglobin studies before deciding on a much longer procedure.