Extended Data Fig. 6: RT-qPCR assay to detect GBS 16S rRNA.
a, Schematic diagram of the RT-qPCR strategy. b, qPCR amplification plot representing 3 positive samples with signal for GBS 16S rRNA (green, blue and red curves), 1 negative sample with no 16S signal (yellow curve) and 2 negative controls samples (H2O or without the reverse transcriptase enzyme in the RT reaction in black and grey, respectively). Placental samples were run in duplicate and were considered GBS positive if both wells had signal for 16S rRNA. The relative abundance of the target is expressed using the Ct (cycle threshold) value, which is inversely associated with the signal. Rn (normalized reporter value) represents the fluorescence of the reporter dye normalized to the signal of the passive reference dye for a given reaction. The ΔRn is the Rn value of an experimental reaction minus the Rn value of the baseline signal generated by the instrument. This parameter indicates the magnitude of the fluorescent signal generated in the qPCR assay. RT denotes reverse transcriptase.
