Comparative interference by haemolysis inautomated assays for bilirubin at multiple analyte concentrations

[摘要] The negative interference caused by haemolysis in manual bilirubinassays contrasts with the positive interference reported for someautomated methods utilizing the same basic chemistry. Acomparison was therefore made of the haemolysis interferenceassociated with several automated bilirubin methodologies: multilayerfilm (Kodak Ektachem- total bilirubin (TBil), directbilirubin (DBil), conjugated bilirubin (Bc), unconjugated bilirubin(Bu),; tableted reagents (Baxter Paramax- TBil, DBil);continuous flow (Technicon SMAC — TBil). Thirty serum poolswere analysed (five concentrations of bilirubin, 2-229 μmol/l; sixconcentrations of haemoglobin, 0.00002-0.052 mmol/1). Allmethods, except one (Bc), exhibited both positive and negativeinterference, depending upon the relative haemoglobin and bilirubinconcentrations. This interference, at any given haemoglobinconcentration, was neither constant nor proportional with increasingbilirubin concentration. These complex patterns of interferencesuggest that the best characterization of interference is obtainedwhen (1) both percentage-difference and absolute-difference‘interferographs’ are plotted; and (2) the interference is determinedat multiple analyte concentrations.

[学科分类] 分析化学