Metagenomic Assay for Identification of Microbial Pathogens in Tumor Tissues

Baldwin, Don A.; Feldman, Michael; Alwine, James C.; Robertson, Erle S.

reads that mapped to the HPV16 genome from all sample pools; the x axis shows map coordinates scaled to match the transcript map. (B) PCR using the forward (fwd) and reverse (rev) primers shown in panel a detected at least one HPV16 region in samples with hybridization to most or some PathoChip HPV16 probes and no detection in samples that were negative for PathoChip signal or were no-template controls. The m1 marker is phiX174 HaeIII digest, and the m2 marker contains the four amplicons produced from a plasmid carrying the HPV16 genome. (C) The individual reads obtained from cap-seq are shown for the sample pools from panel A. Pool 1 contained seven samples with low or no hybridization signal to HPV16 probes in PathoChip screening assays; 71% of the remaining samples were positive for PathoChip HPV16 detection. Whole-genome amplified DNA plus cDNA was hybridized to a set of six biotinylated HPV16 probes, captured on streptavidin beads, and used for tagmentation library preparation and deep sequencing with paired-end 250-nt reads. (Tagmentation is the process of tagging the fragmented DNA generated during library perpetration.) Reads (gray arrows) that map to the HPV16 reference genome sequence (blue) cluster around the capture probe locations (red segments in the 1-kb coordinate map), but templates up to 3 kb away from a capture probe were also recovered. card value of 0%. Candidate regions were classified by MAT scores of 30 to 300, 300 to 3,000, and Ͼ3,000.