Figure 2
(a–f) qPCR and (g–l) LAMP experiments demonstrate reaction inhibition from NA extraction kit buffers. Quantification cycles (Cq) for qPCR or time to positive (TTP) for LAMP spiked with 5 × 104 copies λ phage DNA and primers with increasing concentrations of extraction kit buffers. For ethanol dilutions (a,g), three separate amplification mixes were each combined with an independent ethanol dilution series. All remaining buffer dilutions (b–f,h–l) shared the same set of three amplification mixes (same 0% condition), and each amplification mix was combined with an independent dilution series of each buffer. Each bar is the average of qPCR or LAMP technical triplicates (black circles). Where shown, numbers above a bar indicate the number of samples that amplified out of technical triplicates. Gray shading indicates when inhibition (>0.5 cycles or >0.5 min) was observed according to changes in Cq or TTP. Samples marked N.D. were not detected within either 40 cycles or 40 min.
