New system for automated extraction and simultaneous determination of serum cholesterol and triglycerides

We describe an automated system for serum lipid extraction and simultaneous determination of cholesterol and triglycerides, with use of continuous-flow equipment. A sample volume of 100 mul of serum is required, and samples are processed at the rate of 20 per hour, which may be increased with slight loss in precision. Time from sample pickup to recorder readout is about 25 min. The system makes use of established colorimetric reactions, and the values obtained agree with ranges currently reported in the literature. Correlation coefficients for results of the automated and manual methods were 0.98 for cholesterol and 0.99 for triglycerides, and the day-to-day coefficients of variation were 1.8% for cholesterol (1 SD equal to 34 mg/liter) and 3.4% for triglycerides (1 SD equal to 37 mg/liter). The small sample volume, precision, accuracy, speed, and comparative economy of reagents make this system particularly suitable for multiphasic screening, pediatrics, and small-animal research.