Modified Jendrassik--Grof method for bilirubins adapted to the Abbott Bichromatic Analyzer

Area of Science:

• Clinical Chemistry
• Analytical Biochemistry

Background:

• Bilirubin levels are critical indicators of liver function and hemolytic disease.
• Accurate and efficient bilirubin determination is essential for timely clinical diagnosis.
• Existing automated methods may require larger sample volumes or lack specific advantages.

Purpose of the Study:

• To develop and validate a semi-micro method for quantifying total and direct bilirubins.
• To assess the method's performance characteristics, including accuracy, precision, and linearity.
• To address potential interferences in bilirubin assays.

Main Methods:

• Utilized a discrete analyzer (Abbott ABA-100) with a 75 microliter sample volume.
• Employed a serum blank and measured azobilirubin color development at 550 nm.
• Investigated and mitigated interference from hemoglobin and its derivatives using caffeine and acid blanks.

Main Results:

• Achieved comparable results to the automated Jendrassik and Grof procedure (total r = 0.999, direct r = 0.990).
• Demonstrated linearity up to 300 mg/liter.
• Showcased good day-to-day precision (CV 8.8% and 4.7% for different concentrations).

Conclusions:

• The described semi-micro method provides a simple, rapid, and accurate means for determining total and direct bilirubins.
• The method is suitable for clinical laboratory use, offering a low sample volume requirement.
• Effective strategies were implemented to overcome common assay interferences.