Modification of the DuPont aca as exemplified by a new procedure for neonatal total bilirubin.

Hemoglobin interferes with determination of total bilirubin by the diazo procedure with the DuPont aca. We compared results by that procedure with those by a manual direct spectrophotometric two-wavelength method. Because the manual method was not inhibited by hemolysis as was the DuPont aca diazo procedure, we reprogrammed our DuPont aca to measure the absorbance of diluted serum samples at 452 and 577 nm with use of DuPont absorbance packs as the sample pack and cuvette. Results correlated well with those by the manual spectrophotometric method, and hemolysis no longer interfered. The method is primarily intended for use with serum from neonates.