Fig. 2

Bias in miRNA detection using various small-RNA library preparation kits. For each kit, sequencing libraries were prepared from the miRXplore™ pool and sequenced; the sequence data were then used to calculate fold-deviations from the equimolar input and plotted as log₂ values. Densities of miRNAs within a two-fold deviation from the expected values (between vertical lines) are considered unbiased according to [8]. Under-represented, over-represented, and accurately quantified percentages of miRNAs are shown in red font. Results for two-adapter schemes are a TruSeq® Small RNA, b NEBNext®, and c QIAseq. d NEXTFlex™, a scheme using two adapters with randomized sequences. e SMARTer, which uses template switching. f RealSeq®-AC, which uses a single-adapter and circularization (*p value vs other kits < 0.005)