Enzyme Thermistor Assays of Cholesterol, Oxalic Acid, Glucose and Lactose in Standard Solutions and Biological Samples

Abstract

Thermal analysis is, in principle, a non-specific technique which thus is suitable as a general monitor for complex processes, such as cell metabolism (1). The combination of thermal analysis and highly specific enzymes offers a very powerful analytical technique. Using immobilized trypsin placed in a flow-cell in a LKBsorption microcalorimeter the enzyme-catalyzed hydrolysis of the ester substrate, BAEE, was measured (2). The calorimeter gave accurate results but the long time required for each measurement stressed the need for a more rapid analytical method for routine work. Therefore a simple, inexpensive device named “the enzyme thermistor” was constructed.