Figure 5

Tests for mouse DNA. A) TaqMan qPCR for murine mitochondrial cytochrome oxidase (mcox2). Titration of DNA from the murine EL4 cell line (100, 10, 1, 0.1, and 0.01 cell equivalents) in the absence (triangle, solid line, slope = -3.58) or in the presence of 3.3 × 10⁴ cell equivalents of background genomic LNCaP DNA (square, dotted line, slope = -2.58). 0.1 cell equivalents of murine DNA were observed in 3.3 × 10⁴ cell equivalents of background DNA. Samples were run in duplicate. All qPCR reactions were run for 60 cycles. Samples that did not produce a signal after 60 cycles were considered negative for murine DNA. B) IAP PCR. Titration of DNA from the murine EL4 cell line (10, 1, and 0.1 and 0 cell equivalents) in the presence of 3.3 × 10⁴ cell equivalents of genomic LNCaP DNA. The limit of detection was 0.1 cell equivalents of murine DNA in 3.3 × 10⁴ cell equivalents of background DNA. Although not visible here, bands of different sizes and unrelated sequence are sometimes visible in samples analyzed with human DNA alone. NTC = No Template Control.