Different effect of Intralipid and triacylglycerol rich lipoproteins on the Kodak Ektachem serum cholesterol determination.

We documented the quantitative effects of lipaemia on cholesterol recovery on a Kodak Ektachem 700 XRC analyser (Rochester, NY, USA) in comparison with a Hitachi 717 analyser (Boehringer, Mannheim, Germany). Using the linear ranges of the analysers, we compared the effects of adding Intralipid and of adding high concentrations of native Very-Low-Density-Lipoproteins and/or chylomicrons. Our data demonstrate less than 10% bias for the Kodak cholesterol determination in an Intralipid dilution series prepared according to M. R. Glick and coworkers (e.g. Clin. Chem. 33 (1987) 1453-1458). However, in a hypertriglyceridaemic dilution series (theoretical cholesterol concentrations ranged from 5.2 to 15.5 mmol/l) the Kodak cholesterol recovery fraction decreased from 0.88 to 0.58 when the triacylglycerol concentration increased from 5.64 mmol/l to 38.35 mmol/l. In contrast, the cholesterol recoveries on the Hitachi analyser were complete for both approaches. We conclude that the lipaemia effect on the Kodak cholesterol determination is not adequately reflected by addition of Intralipid, because the Kodak cholesterol determination is more prone to interference by turbidity when triacylglycerols are presented as native serum lipoproteins, especially as chylomicrons.