Determination of Non-Albumin-Bound Bilirubin in Human Serum

Abstract

Determinations of the low equilibrium concentrations of non-albumin-bound unconjugated bilirubin in serum by a kinetic method have been done on normal umbilical cord blood serum, on serum from exchange transfusions of icteric newborns, and on normal adult serum. The concentrations are about 10⁻⁹ M in cord serum and in adult serum, and about 10⁻⁵ M in the icteric infant sera. The latter shows little correlation between total unconjugated bilirubin and non-bound bilirubin, indicating that there is a considerable variation in the binding of bilirubin to albumin.