18] Biomedical applications of the enzyme thermistor in lipid determinations

Abstract

Determination of lipids in human body fluids is of great importance in medical health care. Measurement of lipid content, for example, cholesterol, triglycerides, and phospholipids, provides important information in the diagnosis of diseases. Most serum lipids are solubilized as lipoproteins and therefore have a large aggregate molecular weight. Triglycerides remain mainly as chylomicrons and low density lipoproteins. By the use of rather large pore-size controlled-pore glass, diffusion problems caused by steric hindrance of the large substrate are avoided. Similar approaches using immobilized enzymes coupled with electrochemical devices have been successfully performed. Rapid and continuous determination of lipids is possible with the enzyme thermistor. The use of enzyme thermistor devices is simple, reliable, and economical in the biomedical field. Because of these advantages, the enzyme thermistor as a thermal bioanalyzer appears quite promising and very attractive for use in routine clinical analysis. Direct and continuous assays for free cholesterol and esterified cholesterol in serum based on the enzyme thermistor are now under investigation in the laboratory.