Figure 2.

Overview of barcoded pyrosequencing workflow. The sample-specific barcodes are introduced into each sample during the PCR step (for amplicon sequencing), or through ligation (for metagenomics). After sequencing, individual sequences can then be traced back to individual samples using the barcodes they contain. The sequences from each sample are then separated, aligned, and then either used directly for taxa-based analyses or used to build trees for phylogenetic analyses. OTU, operational taxonomic unit.