Assays of drugs by immunological methods

Among the methods of choice for routine drug measurements in biological fluids, such as GC, HPLC, GC-MS, TLC, and RIA and enzyme immunoassays, the technique with the most potential is immunoassay, which is simple, inexpensive and rapid, and can potentially be automated. The future development of further antisera, highly specific to various drugs and their metabolites, will undoubtedly lead to immunoassay as the method of choice for routine analysis. Recent advancement is monoclonal antibody production by hybridoma technique is already offering some promise to such possibilities. Although the use of enzyme as a label of choice in immunoassay has been rapidly growing in recent years, utilization of such enzyme is certain instances, is restricted. Even though enzyme immunoassay has various advantages over RIA, such as no potential radiation hazards and a long shelf-life of the enzyme label, it is anticipated that simplicity and ease for manipulation permits the use of radioisotope indispensable in immunoassay for many more years to come