An integrative protocol for one-step PCR amplicon library construction and accurate demultiplexing of pooled sequencing data

High-throughput sequencing of amplicons has been widely used to precisely and efficiently identify species compositions and analyze community structures, greatly promoting biological studies involving large amounts of complex samples, especially those involving environmental and pathogen-monitoring ones. Commercial library preparation kits for amplicon sequencing, which generally require multiple steps, including adapter ligation and indexing, are expensive and time-consuming, especially for applications at a large scale. To overcome these limitations, a "one-step PCR approach" has been previously proposed for constructions of amplicon libraries using long fusion primers. However, efficient amplifications of target genes and accurate demultiplexing of pooled sequencing data remain to be addressed. To tackle these, we present an integrative protocol for one-step PCR amplicon library construction (OSPALC). High-quality reads have been generated by this approach to reliably identify species compositions of mock bacterial communities and environmental samples. With this protocol, the amplicon library is constructed through one regular PCR with long primers, and the total cost per DNA/cDNA sample decreases to just 7% of the typical cost via the multi-step PCR approach. Empirically tested primers and optimized PCR conditions to construct OSPALC libraries for 16S rDNA V4 regions are demonstrated as a case study. Tools to design primers targeting at any genomic regions are also presented. In principle, OSPALC can be readily applied to construct amplicon libraries of any target genes using DNA or RNA samples, and will facilitate research in numerous fields.