Establishment of Hybridization Assay with Nucleic Acid Probe Detect IBDV andComparison witIl Immunodiffusion Test

The hybridization assay with digoxigenin(DIG)-labeled probe was developed for detection of in-fectious bursal disease virus(IBDV)and it's semitivity was compared with that of immunodiffusiontest in this experiment.IBDV STC-119 and STC-24 3 cDNA fragments used as probe were preparedfrom recombinant pUC plasmid with Hind Ⅲ and EcoRI and labeled with DIG.IBDV RNA was ex-tracted from IBDV purified from chicken bursa which were homogenized followed by extraction withchloroform,precipitation of virus with immune serum,digestion with proteinase K and recovery of IBDV RNA with ethanol precipitation.The results show that 0.lpg of IBDV RNA can be positively de-tected by this method and the mixed probe were able to hybridize with RNA from several IBDV isolatesand can be used for diagnosis of infectious bursal disease in the early stage of infection.The comparisonwith immunodiffusion test revealed that the furmer is l04 times more sensitive than the later,More-over,the specificity and the convenience of nonradioactive pro