Figure 1.

Principles of LAMP assay. During the initial stages of the LAMP reaction, the inner primers (FIP or BIP) anneal to regions F2c or B2c within the target region. The LAMP reaction is initiated by strand invasion by the inner primers, and a strand displacement DNA polymerase extends the primer and separates the target DNA duplex. The outer primers (F3 or B3) then hybridizes to region F3c or B3c on the target and initiates the formation of self-hybridizing loop structures by the strand invasion. This results in the formation of a dumbbell-shaped DNA, which becomes a seed for exponential amplification. As a result of this process, various sized structures consisting of stem-loop DNA with various stem lengths and various cauliflower-like structures with multiple loops are formed. The addition of loop primers (LF and LB) can accelerate the process.