Detection of Tobacco Bacterial Wilt Caused by Ralstonia solanacearum by Combining Polymerase Chain Reaction with an α-Hemolysin Nanopore.

Tobacco bacterial wilt is a serious disease caused by the soil-borne bacterium (). Herein, a rapid and purification-free α-hemolysin (α-HL) nanopore-sensing strategy based on polymerase chain reaction (PCR) and lambda exonuclease digestion was established to detect . A 198-nucleotide-long single-stranded DNA was obtained via asymmetric PCR or the lambda exonuclease-mediated digestion of the PCR product. The DNA fragment produced unique long-lived, current-blocking signals when it passed through the α-HL nanopore. This sensing approach can allow for the determination of in tobacco samples and can be conveniently extended to other DNA monitoring because of the extremely wide range of PCR applications.