Blue LAMP: A fast and reliable nucleic acid amplification technique for the detection of Plum pox virus

So far, the polymerase chain reaction (PCR) is the most widely used method for the amplification of nucleic acids in vitro, especially for pathogen detection because of its high sensitivity. However, numerous isothermal amplification methods were developed in the recent years to avoid the need for a thermal cycler. Meanwhile the most applied approach is loop-mediated isothermal amplification (LAMP). The great advantage of LAMP is the enormous rate of amplification paired with a very high specificity. This study presents a simplified procedure for Plum pox virus (PPV) detection. A crude plant extract was applied to a modified one-step RT-LAMP protocol of Varga and James (2006). Gel electrophoresis was circumvented by a colour change of the reaction mix upon nucleic acid amplification. This procedure takes only two and a half hour from sampling to result and requires minimal technical equipment. The risk of cross contamination is minimized since amplification and visualization take place in a single tube. The Blue LAMP provides a fast and reliable detection of PPV both for single samples and for large scale surveys.