Polymerase chain reaction-based restriction fragment length polymorphism pattern of porcine reproductive and respiratory syndrome virus directly fromlung tissues without virus isolation in Korea

Polymerase chain reaction (PCR)-based restriction fragment length polymorph ism (RFLP) analysis was developed for directly typing porcine reproductive and respiratory syndrome virus (PRRSV) from lung specimens without virus is olation. Twenty nine lung specimens collected from postweaning pigs were is olated for PRRSV. When the PCR products from the 29 lung specimens were dig ested by the restriction enzymes MluI, HincII, SacII and HaeIII, the RFLP p atterns from the 29 lung specimens matched with those from the correspondin g PRRSV isolates from each pig. The results suggest that the PCR-based RFLP analysis method may be useful to distinguish PRRSV isolates directly from lung specimens without virus isolation.