Review on “Evolution of Methods of Bilirubin Estimation”

Abstract

Bilirubin is an end product of heme metabolism, which is under disposal of tissues like liver, intestine and kidney. Clinically hyperbilirubinemia appears as jaundice or icterus. Jaundice can usually be detected when the serum bilirubin level exceeds 2.0 to 2.5 mg/dl. Determination of total and direct bilirubin levels helps the physician to know the underlying pathogenic mechanism. Hence accurate and unbiased estimation of bilirubin becomes mandatory. The problem of finding an accurate and specific method of bilirubin assay has been a challenge for over 50 years for many workers. Historically, Ehrlich in 1883 treated bilirubin in urine with diazo reagent and described formation of a red – blue coloured pigment. Later, Van den Bergh and Muller found that bilirubin in normal serum reacted with Ehrlich's diazo reagent (diazotized sulfanilic acid). We shall discuss here the further evolution of methods of bilirubin estimation till the modern era and also will cover the various aspects of interpretation and quality control measures.