Patent ID: 8865409

Claim:
A method for the quantification of a vaccine strain, and a virulent strain of Marek's Disease Virus Serotype-1 (MDV-1) in a sample from a bird, comprising the steps of: (i) providing a biological sample from the bird; (ii) subjecting the biological sample of (i) to real-time quantitative PCR (qPCR) comprising: (a) amplification of a region of the pp38 gene within the nucleic acid sample of (i), said region containing a consistent single nucleotide polymorphism (SNP) difference between vaccine and virulent strains of MDV-1, wherein the amplification step is performed with the following nucleic acid amplification primers: Forward primer: 5′ GAGCTAACCGGAGAGGGAGA 3′ set forth in SEQ ID NO:5 and Reverse primer: 5′ CGCATACCGACTTTCGTCAA 3′ set forth in SEQ ID NO:6; and (b) contacting the amplified nucleic acid of (a) with a detectable nucleic acid probe specific for the SNP of the vaccine strain and a detectable nucleic acid probe specific for the SNP of the virulent strain of MDV-1 wherein said detectable nucleic acid probes comprise the vaccine strain-specific probe set forth in SEQ ID NO: 1 and at least one of the following virulent strain-specific probes: SEQ ID NO: 2 and SEQ ID NO: 3; and (iii) measuring the detectable signal produced by each of the vaccine strain probe and the virulent stain probes of (ii); and (iv) comparing the detectable signal measured in (iii) for each specific probe to determine the amount of virulent and vaccine strain present in the sample.