Recombinant DNA and other direct specimen identification techniques.

DNA molecules and monoclonal antibodies can now be employed in the clinical laboratory to detect microorganisms in clinical samples. DNA probes are produced by cloning specific gene sequences which then react with homologous target DNA in the sample by DNA hybridization. Monoclonal antibodies are also produced by selection, cloning, and tagging, much like DNA probes. Both methods appear to be highly sensitive, specific, and rapid in the detection of microorganisms.