Determination of total and direct bilirubins in serum with sodium dodecyl sulfate as an accelerator.

A new method for the determination of total and conjugated bilirubins in serum with use of sodium dodecyl sulfate (SDS) is described. In the presence of SDS, the reaction of bilirubin with diazotized sulfanilic acid proceeded smoothly and was completed within 15 min at room temperature, thus resulting in a clear solution having a maximal absorbance at 565 nm which was linear up to a level of 200 mg/l bilirubin concentration. The advantages of this method are: (1) a clear reaction mixture results in any case; (2) the result is not affected by hemolysis, lipemic and turbid sera. The proposed method offers a new general application for the measurement of total and conjugated bilirubins in serum.