Normal Bilirubin Concentration and the Occurrence of Othek Bile Pigments in Human Blood Sera

Abstract

Unconjugated serum bilirubin of 114 blood donors was estimated by the chloroform extraction method. Average values and standard deviations were found similar to previously established values, obtained by methods for determination of total bilirubin. The average for males is significantly higher than for females.A bilirubin derivative can be demonstrated in small concentrations in a large proportion of blood donor sera. Its proporties are similar to those of the alkali-stable bilirubin conjugate of human bile.Nine infants with varying degrees of neonatal jaundice were found to have unconjugated bilirubin as their major, or only, serum bile pigment.