Used in diagnostic assays to detect the presence of viral nucleocapsid proteins, particularly in immunoassays such as ELISA and lateral flow tests. Commonly applied in research and clinical settings to identify viral infections, including coronaviruses, by targeting the nucleocapsid antigen. Also utilized in Western blotting and immunofluorescence for specific detection of viral components in infected cells. Supports development and validation of test kits for infectious disease screening.