The

so-called direct bilirubin and total bilirubin are estimated. The reagent is

diazotized sulfanilic acid, reaction with bilirubin produces an azo dye, the

absorbance of which is measured.

Direct

bilirubin reacts directly with the reagent, we must use an accelerator to

determine the total bilirubin.

The

accelerator ensures:

Thus,

direct bilirubin is bilirubin:

Indirect

bilirubin is:

indirect bilirubin level = total bilirubin - direct bilirubin