Real-time reverse transcription-polymerase chain reaction (RT-PCR) assays are common diagnostic tests used as a screening tool for IAV infections in many laboratories on ante and postmortem samples that may include oral fluid, nasal secretions and lung tissue. RT-PCR is a rapid, sensitive and specific test based on detection of IAV genetic material, or RNA, with a quick turn-around time. In addition, RT-PCR can be used to subtype influenza infections and determine if the virus is H1N1, H1N2 or H3N2. RT-PCR results from antemortem samples should be interpreted with caution considering a positive result may be obtained from non-clinical animals in spite of the presence of the virus. Influenza sequencing of specific genes, such as the hemagglutinin, and virus isolation are also available when characterizing a particular IAV in a population.