Real-time PCR. The plot shows the amplification obtained using TaqMan probes with the same DNA sources as those used for the nested PCR that yielded positive results. The probes are based in a different region of the env gene, namely from 5943 to 6011 (AF033807). Each line represents a sample, positive control, or negative control. The PCR cycles are shown on the x-axis, and the ΔRn values (representing the fluorescent units) are shown on the y-axis. All of the assays were performed in 48-well plates.