Criterion: Recovery within plus or minus 10% of initial value. Icterus: No significant interference up to an I index of 60 for conjugated bilirubin and 60 for unconjugated bilirubin (approximate conjugated bilirubin concentration: 30 mg/dL; approximate unconjugated bilirubin concentration: 60 mg/dL). Hemolysis: No significant interference up to an H index of 1200 (approximate hemoglobin concentration: 1200 mg/dL). Lipemia (Intralipid): No significant interference up to an L index of 2000. There is poor correlation between turbidity and triglycerides concentration. The claim for lipemia interference is based on the Glick model (1), which uses Intralipid as an artificial substrate. To date, there is no model available which can mimic interference by triglycerides, as triglyceride levels in patient specimens behave unpredictably, depending on the nature of the esterified fatty acids in the samples. Patient specimens with elevated triglyceride levels are very often lipemic. Therefore customers cannot verify interference by triglycerides in patient specimens. Ascorbic acid less than 50 mg/dL. In rare cases, elevated immunoglobulin concentrations can lead to falsely increased HDL-cholesterol results. Abnormal liver function does affect lipid metabolism; consequently, HDL and LDL results are of limited diagnostic value. In some patients with abnormal liver function, the HDL-C plus result is significantly negatively biased versus the DCM (designated comparison method) result. Of 17 commonly used drugs tested in vitro, none interfered with the assay. Reference: Glick MR, Ryder KW, Jackson SA. Graphical Comparisons of Interferences in Clinical Chemistry Instrumentation. Clin Chem 1986;32:470-474.