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Fig. 1 | BMC Microbiology

Fig. 1

From: Decontamination of 16S rRNA gene amplicon sequence datasets based on bacterial load assessment by qPCR

Fig. 1

Bacterial load assessed by qPCR. The universal bacterial primers used in qPCR target the V3 segment of the 16S rRNA gene. Bacterial loads were determined using the standard curves obtained with S. aureus MW2 (a) or E. coli DH5α (b) genomic DNA. The S. aureus and E. coli genomes weigh approximately 2.9 and 4.8 fg and contain six and seven 16S rRNA gene copies, respectively. Each symbol (Exp1, Exp2 and Exp3) corresponds to the series of aliquots processed at a given point and represents the mean of duplicate measurements with relative deviations from the mean <2.5 %. Bacterial load is expressed as the number of E. coli or S. aureus genome equivalents in 1 μl of DNA extract. Serial decimal dilutions of the master stock are indicated from 1E0 (no dilution) to 1E-8 (10−8). SA, S. aureus; EC, E. coli. NEC_B, negative extraction controls obtained by substituting culture for lysis buffer; NEC_W, negative extraction controls obtained by substituting culture for water; NTC_W, no template (qPCR) control reactions performed by substituting DNA extract for water

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