[Isoelectric fractions of healthy human serum albumin and their ability to bind bilirubin].

The article deals with the isoelectric spectrum of human serum albumin isolated by electrophoresis in polyacrylamide gel, on agar-agar, by salting out with ammonium sulphate and also by the Cohn method. It is shown that the way of albumin isolation, except the Cohn method, does not affect the quantitative and qualitative characteristics of its isoelectric spectrum obtained on ampholines by focusing. Fractions isolated from healthy people have always pI 4.7, 5.1, 5.5, their ratio being different. Albumin and its fractions are identical immunochemically. Dispersion of the fraction content optic rotation, except the fraction with pI 5,1, is the same as in initial albumin. Bilirubin is bound mainly (80%) by the fraction with pI 4.7 and it is absent in the fraction with pI 5.5.