Human serum bilirubin; an immediate method of determination and its application to the establishment of normal values.

IT AN ATTEMPT TO DETECT TNE CARRIERS of homologous serum hepatitis (HSH), determination of bilirubin in all sera appearing more yellow than normal was instituted at the Red Cross Blood Transfusion Service in Brisbane in 1949. While the estimation did not prove successful as an unequivocal test for HSH carriers, the results brought to light interesting findings both in regard to the methods for estimating bilirubin and to the serum bilirubin levels in normal people. Most modern methods for serum bilirubin estimation involve diazotization followed by treatment with reagents such as methyl and ethyl alcohol, sodium hydroxide, bile acids, citric acid, urea, caffeine, sodium benzoate, or sodium acetate. In our experience, the widely used methods involving the use of alcohols, such as those of Thann. hauser and Anderson (1) and of Malloy and Evelyn (2) and recent modifications thereof, may result in some turbidity in the final solutions, making them particularly unsuitable for use in the determination of low values. Further, they take undue time to perform and involve high dilutions of the azo-pigment. A modification of the method of Powell (3) was found to be most