ABSTRACT
The area of radioimmunoassay procedures is one of the most rapidly growing subdisciplines of the clinical laboratory. Although the majority of the procedures utilize serum as the specimen of choice, there are many methods which have been adapted for use with urine, as well as many which have been designed to measure specific urine constituents. One of the biggest advantages to radioimmunoassay procedures is that they provide information which was not previously available. These are, for the most part, new procedures which determine constituents of urine never before assayed with such quantitation and accuracy. Obtaining good reagents and caring for them properly is a must with all methods in the clinical laboratory. However, it is particularly important with radioimmunoassay reagents. Refrigeration and freezer storage is mandatory for some, and the usable time after reconstitution of some of the reagents is measured in hours.
