Loop-mediated isothermal amplification for rapid detection of Newcastle disease virus.

We have evaluated a diagnostic system based on the loop-mediated isothermal amplification (LAMP) assay for the rapid, simple, and sensitive detection of Newcastle disease virus (NDV) directly from culture isolates as well as clinical samples. By using one set of specific primers targeting the fusion protein gene, the LAMP assay rapidly amplified the target gene within 2 h, requiring only a regular laboratory water bath or heat block for reaction. The results obtained from testing the genomes of 38 NDV strains, other different viruses, and clinical samples of experimentally infected chickens showed that LAMP was as sensitive and specific as nested PCR. All LAMP-positive samples were positive by nested PCR. The LAMP assay is faster than nested PCR, cost-effective, and easy to perform. Our results clearly demonstrate that the LAMP-based assay is a useful tool for the rapid and sensitive diagnosis of NDV infection.