Schematic of DK-MICROBE. Tissue of interest may have four potential microbial association states: (A) human cells associated with surrounding microbes, (B) human cells with integrated foreign DNA, (C) human cells with non-integrated foreign DNA, and (D) human cells with no foreign DNA. Sequential restriction digests by SacI (restriction sites indicated by "S") and NlaIII (indicated by "N") result in sequence tags derived from foreign DNA sequences (red boxes), and human sequences (blue boxes). Small ovals represent linkers while large brown ovals represent streptavidin-coated magnetic beads. Experimental tags are matched to microbial virtual tag library, representing all known microbial reference genomes. Unmatched tags include human sequences.