Loop-mediated isothermal amplification assay for the rapid and visual detection of novel porcine circovirus 3

A loop-mediated isothermal amplification (LAMP) assay using hydroxynaphthol blue was developed for the rapid and visual detection of the capsid gene of porcine circovirus 3 (PCV3). The amplification could be completed in 40 min at 62°C, and the results could be visually detected by the naked eye. The assay specifically amplified PCV3 DNA and not other porcine viral nucleic acids. The limit of detection of the assay was 50 PCV3 DNA copies, which was comparable to that of the real-time polymerase chain reaction (qPCR) and lower than that of conventional PCR. In the clinical evaluation, the PCV3 detection rate of the LAMP assay was higher than that of PCR and agreed 100% with that of qPCR. These results indicate that the LAMP assay will be a valuable tool for the rapid, sensitive, and specific detection of PCV3 in clinical samples.