Single-stranded conformation polymorphism and MPAC patterns of Mycobacterium tuberculosis strains harboring gyrA mutations. (a) Single-stranded conformation polymorphism patterns of PCR products generated with primers 3F/3R. (b) MPAC patterns of multiplex PCR products generated with primers 1F/1R, 2F/2R, and 3F/3R in a single reaction. (c) MPAC patterns of a mixture of two PCR products generated by primers 2F/2R and primers 3F/3R, respectively. A, Strains ATCC 27294 and ATCC 25177; B, no mutation in the region encoding amino acids 90 through 94; C, Ala90→Val; D, Ser91→Pro; E, Asp94→Gly; F, Asp94→His; G, Asp94→Tyr; H, Asp94→Ala; I, Asp94→Asn. Apart from the two ATCC strains, all isolates contained a Ser→Thr substitution at position 95; hence, patterns A and B are different.