VP1 gene based RT-PCR/restriction enzyme analysis for the characterization of infectious bursal disease virus strains

We report here differentiation of field isolates, vaccine and classical strains of infectious bursal disease virus by restriction enzyme analysis of an RT-PCR amplified portion (480bp) of VPl gene sequence. Restriction enzymedigestion of PCR products with HindIII enzyme revealed presence of a single site in field isolates and no site in vaccine or classical strains, whereas digestion with Rsal enzyme showed single site in classical and vaccine stains and two sites in field isolates. Therefore, these two enzymes can be used to differentiate very virulent field isolates from the classical and vaccine strains.