Determination of the sensitivity of amplification by RT-PCR of the ABPV. ABPV virus stock containing 1.6 × 107 genome copies/μl was serially 10-fold diluted. One microliter of this stock was used in the RT-PCR mixture. M, Pst lambda DNA marker; lane 1, ABPV; lane 2, 10−1 ABPV dilution; lane 3, 10−2 ABPV dilution; lane 4, 10−3 ABPV dilution; lane 5, 10−4 ABPV dilution; lane 6, 10−5 ABPV dilution; lane 7, water (negative control).