ABSTRACT
Prior to the 1970s, microorganisms were primarily identified with conven tional biochemical tests and often required several days to weeks for identi fication. In the early 1970s, API (bioMerieux Vitek) introduced lyophilized substrates in microcupules that allowed many clinical isolates to be identi fied in 24-48 hr. Subsequently, with use of a heavy inoculum, preformed enzymes could be detected, allowing some bacteria to be identified in 4 hr. In the latter half of the 1970s, automated identification systems were intro duced. Our discussion will be limited to identification systems that have automated result entry, have a data base for the identification of a large variety of different microorganisms and are available in the United States.
