Diagnostic Tests for Viral Infections | Serology, PCR and Viral Culture Explained

Discover how PCR, antigen tests, viral culture, and serology work to diagnose viral infections — learn which test to use and when. This video breaks down PCR (including RT-PCR), rapid antigen tests, viral culture, and antibody serology, explaining how each detects virus, viral proteins, or the immune response, and why timing and sample type matter.

You’ll learn how PCR amplifies viral genetic material (DNA or RNA) for high sensitivity early in infection, when nasal, throat, lesion, or blood samples are best; why antigen immunoassays provide faster but less sensitive results useful for rapid screening of COVID-19, influenza, and RSV; and when viral culture is still valuable for proving live virus, investigating unknown pathogens, or testing antiviral susceptibility. The video also clarifies serology: how IgM and IgG antibodies indicate recent versus past exposure, examples with CMV and EBV, and how serology complements PCR for staging infection or assessing immunity.

Key benefits: understand test sensitivity, appropriate sample selection, and optimal timing to improve diagnosis accuracy; learn practical applications like confirming shingles from lesion swabs, using RT-PCR for SARS-CoV-2, or interpreting antibody panels for past exposure. Technical terms (RT-PCR, primers, reverse transcriptase, immunoassay, cytopathic effect, IgM/IgG) are explained clearly so clinicians, students, and informed viewers can apply this knowledge.

Watch to master which diagnostic test answers specific clinical questions, avoid false negatives, and interpret results with confidence — improve testing decisions and patient care.