**4.11 Polymerase chain reaction (PCR)**

PCR is a molecular diagnostic assay which is used for the detection of viral nucleic acid and is relatively more sensitive than other conventional tests. Diverse antigenic types of the CPV can be distinguished by employing strain-specific primer or nested PCR or restriction enzyme analysis of the PCR. Also strain differentiation may be carried out with the help of oligonucleotide sequencing of the amplified gene [64].
