QUANTITATIVE COMPETITIVE POLYMERASE CHAIN-REACTION FOR DETECTION AND QUANTIFICATION OF INFECTIOUS BURSAL DISEASE VIRUS CDNA AND RNA

A polymerase chain reaction (PCR)-based method to measure complementar y DNA (cDNA) and RNA levels of infectious bursal disease virus (IBDV) was developed. Quantification was achieved by quantitative competitive PCR (QC-PCR) amplification. A competitor, a deletion mutant of the wi ld type IBDV cDNA, was 10-fold serially diluted and co-amplified with IBDV cDNA after being reversely transcribed from the viral RNA. After agarose gel electrophoresis, staining, and densitometric scanning, the bands on the digitized images were analyzed and quantified by compute r-assisted image analysis. Complementary DNA of standard, as well as v ariant strains, of serotype 1 IBDV was detected and quantified using t he same QC-PCR procedures. The assay could measure IBDV cDNA levels ra nging from 1 mu g to 45 fg and RNA levels ranging from 9 mu g to 45 fg . The results indicated that QC-PCR is sensitive, easy to perform. and suitable for routine quantitation of IBDV cDNA or RNA levels. (C) 199 7 Elsevier Science B.V.