The significance of the van den Bergh reaction.

Introduction A REASSESSMENT of the clinical significance of the van den Bergh reaction is rendered highly desirable by the development during the last 15 years of new methods for the determination of bilirubin in body fluids as well as for the estimation of the proportions of the alleged direct and indirect forms of bilirubin. Moreover, modern photo-electric devices permit an accurate measurement of the rate of formation of colour in the van den Bergh diazo reaction, and thereby offer a more objective means of distinguishing between so-called prompt, biphasic, and delayed direct van den Bergh reactions given by jaundiced sera. Van den Bergh and Muller (1916) showed that the presence of alcohol was not necessary in the production of the red pigment azobilirubin by the action of a solution of diazotized sulphanilic acid (the Ehrlich diazo reagent) on bile or sera from patients with obstructive