Figure 3

SYBR Green 1, a non-specific double stranded nucleotide fluorescent probe, can detect a wide range of B. burgdorferi numbers in the presence of mouse DNA. The amplification plots (A) show PCR of the recA gene of B. burgdorferi strain N40 as detected by SYBR Green at the end of each PCR cycle. Uninfected mouse joint DNA (containing 10⁵ nidogen copies) spiked with a ten-fold dilution of B. burgdorferi DNA, starting with 10⁶ spirochete copies, was used for this assay. A standard curve (B) and a direct correlation (r² = 0.947) between Ct number and B. burgdorferi number shows that a wide range of spirochete numbers can be detected in our system using SYBR Green.