Fig. 1. Screening of Mycobacterium paratuberculosis recombinase polymerase amplification-lateral flow dipstick (RPA-LFD) primer and probe. (A) The products of the RPA-nfo reaction were detected by agarose-gel electrophoresis from six primer and probe combinations (F1-LF1-R1, F2-LF1-R1, F3-LF1-R1, F4-LF2-R2, F5-LF2-R2, and F6-LF2-R2; Table 2). (B) ‘a’ shows results of six RPA-nfo reactions on LFD and the DNA template from M. paratuberculosis genomic DNA; and ‘b’ shows negative control (DNase-free water) results for the corresponding combination of primers and probe. Lane 1, F1-R1 (235 bp); Lane 2, F2-R1 (213 bp); Lane 3, F3-R1 (158 bp); Lane 4, F4-R2 (259 bp); Lane 5, F5-R2 (224 bp); Lane 6, F6-R2 (200 bp); M, molecular weight standard (DNA marker 1,000).
