Extended Data Fig. 3: Sensitivity of the sip qPCR and 16S PCR-qPCR assays for GBS detection.

Genomic Streptococcus agalactiae (GBS) DNA was used at 4000, 400, 40, or 4 copies/reaction in the unnested qPCR and the nested PCR-qPCR assays targeting the sip and 16S GBS genes, respectively. The two curves are described by semi-log equations, which were used to calculate the GBS genome copies at 25 Ct (3,855 and 11 copies required for the sip unnested and 16S nested assay, respectively). Means ± standard deviation are shown; n = 4 independent experiments with 2 technical replicates/each. Ct denotes cycle threshold and it is inversely associated with the relative abundance of the target.