FIG. 4.

Quantitative competitive PCR. A preliminary quantitative competitive PCR experiment was carried out to establish the amount of VZV gene 29 DNA in a pooled sample of VZV-positive neurons. This pooled sample was used as the latent VZV standard, and aliquots corresponding to 2, 4, 6, 8, and 10 copies of the latent VZV gene 29 were added to samples containing 10 copies of the internal VZV plasmid standard. The resulting competitive PCR is shown in panel A. The results from the quantitative scan of panel A were used to generate the curve shown in panel B. This curve was used to determine the content of latent VZV gene 29 in multiple samples of 10 neurons. A representative quantitative competitive PCR for 18 tubes containing 10 neuron samples is shown in panel C. Three tubes contained VZV DNA, and the ratio of the band intensities was utilized to determine the copy number. These data are included in Table 4 (as HG-100). The sizes for marker bands of 200 (⇒) and 400 (➞) nucleotides are indicated.