Schematic diagram of primers used in the LAMP assays. In detail, 6–8 distinct regions on every strand were used to design LAMP primers for the target gene. For the inner primers, the forward inner primer (FIP) consisted of the complementary sequence of F1 (F1c), a T-T-T-T linker and F2; the backward inner primer (BIP) consisted of the complementary sequence of B1 (B1c), a T-T-T-T linker and B2. The outer primers F3 and B3 located outside of the F2 and B2 regions, with loop primers LF and LB located beween F2 and F1 or B1 and B2, respectively. The scare bar is 10 nm.