PCR assay for brucellosis real-time PCR for detecting B. abortus A number of different approaches can be used to generate the fluorescence signal. Three approachesSYBR Green I (a double-stranded DNA intercalating dye), 5-exonuclease (enzymatically released fluors), and hybridization probes (fluorescence resonance energy transfer)were evaluated for use in a real-time PCR assay to detect Brucella abortus. The three assays utilized the same amplification primers to produce an identical amplicon. This amplicon spans a region of the B. abortus genome that includes portions of the alkB gene and the IS711 insertion element. All three assays were of comparable sensitivity, providing a linear assay over 7 orders of magnitude (from 7.5 ng down to 7.5 fg). However, the greatest specificity was achieved with the hybridization probe assay(Newby et al., 2003). YL