Direct detection of nasopharyngeal swab samples and specificity test. (a) Fluorescence image of LAMP products from both the B. pertussis extracted template DNA and nasopharyngeal swab sample spiked with B. pertussis bacteria. (b–c) Fluorescence images for the specificity test among B. pertussis, B. parapertussis (b) and B. holmesii (c). In the specificity test, all the detection wells were preloaded with B. pertussis primers; the reaction mixtures with different DNA samples of B. pertussis, B. parapertussis, and B. holmesii (5 × 106 copies per well), as well as the NC (without template DNA), were introduced into different detection wells separately.