Development of a fluorescent loop-mediated isothermal amplification assay for rapid and simple diagnosis of bovine leukemia virus infection

NAGAO, Konomu; MAKINO, Ryohei; APEGO, Francis Victor; MEKATA, Hirohisa; YAMAZAKI, Wataru

The worldwide spread of BLV emphasizes the requirement for early diagnosis and control of disease to minimize economic losses, as well as to ensure animal welfare. The fLAMP assay was applied to rapid and simple diagnosis of human and veterinary infectious diseases [4, 6, 17] . Specific amplification using the LAMP assay occurs at a constant temperature, minimizing reliance on expensive equipment [2, 24] . Consequently, these assays may facilitate the development of an inexpensive test. For example, the fLAMP takes 8-30 min from the beginning of amplification and <10 min for enzyme inactivation and annealing to final judgment. The application of the LAMP assay for rapid screening of clinical samples would save time and costs, enabling detection of BLV-positive cases during the early phase of infection because of its lower or equivalent LODs compared with those of conventional PCR and nested PCR assays [5, 14] . Further, the fLAMP assay can be used at farms, slaughterhouses, and wholesale markets in combination with direct DNA detection techniques of clinical samples [4, 17] , which would enhance the utility of fLAMP when performed using a portable real-time detector such as the Genie III [4, 6] .