Fig. 3: Adapting the PCR-LwCas13a assay for determination of Treponema pallidum lineage. | Nature Communications

Fig. 3: Adapting the PCR-LwCas13a assay for determination of Treponema pallidum lineage.

From: A suite of PCR-LwCas13a assays for detection and genotyping of Treponema pallidum in clinical samples

Fig. 3

a Schematic of PCR-LwCas13a assay for determination of TPA lineage. b–d Fluorescence measurement of Nichols and SS14 clade strains by PCR-LwCas13a-based genotyping. e Dilution experiment to assess the limits of detection of the tp0548-based PCR-LwCas13a genotyping assay. f Ten skin biopsy samples and their corresponding rabbit-passaged TPA isolates were genotyped using the PCR-LwCas13a assay and Sanger sequencing. The phylogenetic tree for tp0548 sequences was constructed using MEGA-X. The tree scale bar indicates the average number of nucleotide substitutions per site. g PCR-LwCas13a assay identified the TPA lineages for 32 of 33 tpp47-positive clinical samples. Squares with color represent positive signals, while white squares represent negative results. Squares with cross represents no positive signals detected by either Nichols or SS14 lineage crRNAs. Abbreviations: A.U. Arbitrary units. n = 3 technical replicates; two-tailed Student t-test was used to analyze the statistical significance; p-value was labeled in the figure, ns = not significant; error bars represent mean ± SEM. Source data are provided as a Source Data file.

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