Novel reagents capable of identifying, or aiding in the identification of, Francisella strains, such as, but not limited to, those identified in playing a role in human diseases or those identified as capable of being used as a biological weapon, are disclosed. In addition, methods for the identification and isolation of the reagents are disclosed. In one embodiment the reagents are peptide sequences. The reagents may be used in diagnostic assays and kits to diagnose the presence of such Francisella strains. In addition the agents identified may be used as research tools for the study and characterization of such Francisella strains.