Direct capture and sequencing reveal ultra-short single-stranded DNA in biofluids

Direct capture and sequencing revealed a new DNA population in biofluids, named ultra-short single-stranded DNA (ussDNA), which was neglected by conventional DNA extraction and sequencing approaches. Evaluation of the size distribution and abundance of ussDNA in biofluids manifested generality of its presence in human, animal, and plants. Red blood cells were found to contain abundant ussDNA with enriched functional elements, and thus possesses great potential as a novel DNA biomarker.