Determination of Serum Urea with an Enzyme Thermistor Using Immobilized Urease

Abstract
The application of an enzyme thermistor device in a simple and accurate procedure for the determination of serum urea is described. The enzyme thermistor measures the heat produced when urea is passed through a small column containing immobilized urease. The stability and sensitivity as well as the performance with clinical serum samples of the system is evaluated. Advantages are the simplicity, the low enzyme cost and the insensitivity to the optical properties of the sample and interfering substances, which may affect the commonly used assay procedures.