Analysis of Effect of Composition of Direct Bilirubin Reagent on Observed Values of Direct Bilirubin in Human Serum

Analysis of Effect of Composition of Direct Bilirubin Reagent

Abstract

Introduction: While total bilirubin methods generally perform satisfactory across laboratories, there is perceived dissatisfaction over direct bilirubin results, particularly negative results in normal ranges, wide variation across labs and direct bilirubin results exceeding total bilirubin. Variation in reagent composition may be responsible for problems observed in direct bilirubin measurement performance. Method: This study was performed to see effect of various direct bilirubin reagents on observed values. 50 mmol/L, 150 mmol/L and 250 mmol/L HCL, water and saline are compared in the study. The study was done by modified Jendrassik diazo method using various composition of reagent R1 for direct bilirubin measurement. The study stratified results in various ranges. Saline and Water gives negative, constant, systemic bias as compared to 50mmol/L reagent for measurement of direct bilirubin. Result: On increasing HCL concentration in the reagent there is increasing negative, proportionate, systemic bias as compared to 50 mmol/L reagent for measurement of direct bilirubin. Discussion: Results of the study indicate need for better uniformity in reagents used for measurement of direct bilirubin to facilitate inter-laboratory comparison of patient result.[Dipti K NJIRM 2017; 8(2):31-34]