Potential interfering substances on Falcor-600 and Dax-48 analytical systems.

The increasing availability and use of automatic analysers in clinical chemistry have revealed a number of endogenous interferences. We evaluated the effect of bilirubin, haemolysis and lipaemia on the Falcor-600 analytical system (Menarini Diagnostics) and the Dax-48 (Bayer Diagnostic). We studied the potential endogenous interferences in the measurement of serum glucose, urea, creatinine, cholesterol, triacylglycerols, total bilirubin, total protein, aspartate aminotransferase, alanine aminotransferase and gamma-glutamyltransferase on both analysers; and albumin, direct bilirubin, uric acid, inorganic phosphorus, iron, calcium, magnesium, chloride, sodium, potassium, alkaline phosphatase, amylase, lactate dehydrogenase and creatine kinase on the Dax-48. We followed the guidelines of the Spanish Society of Clinical Biochemistry and Molecular Pathology. Bilirubin samples were prepared using bovine bilirubin, and studied in the concentration range of 20 to 400 mumol/l. For haemolysis, the pool was spiked with a diluted haemolysate of human red cells to achieve a concentration range of 10 to 120 mumol/l of haemoglobin. Lipaemia was studied using samples spiked with Intralipid, a fat emulsion, at concentrations from 1 g/l to 6 g/l (3 to 18 mumol/l of triacylglycerols).