Bilirubin binding capacity and free bilirubin concentration: fluorescence quenching compared with peroxidase...

Fluorescence quenching was compared with the techniques of peroxidase oxidation and Sephadex column elution for determining free bilirubin concentrations and the capacity of albumin to bind bilirubin and assessed as to its suitability for use as a routine method in a clinical laboratory. The poor reproducibility of the fluorescence quenching method made it unacceptable and peroxidase oxidation was found to be the most satisfactory technique. The Sephadex column elution technique did not measure free bilirubin concentration but gave a good estimate of binding capacity. This method is, however, limited by the sample size required for performing the determinations.