Real-time fluorescence polymerase chain reaction is a microbial identification method that can provide rapid and accurate results using a field-deployable thermocycler, the RAPID ("ruggedized" advanced pathogen identification device). A Yersinia pestis-specific TaqMan assay required approximately 75 minutes and achieved a sensitivity of 100 fg of Y. pestis genomic DNA (20 genome equivalents). Specificity testing against a genomic DNA cross-reaction panel comprised of 22 bacterial species encountered in the respiratory tract resulted in no false positives. No cross-reaction occurred with human genomic DNA.