Used in research and diagnostic applications to detect the spike protein's receptor-binding domain (RBD) of SARS-CoV-2. Helps in studying virus neutralization mechanisms and evaluating immune responses in infected or vaccinated individuals. Employed in immunoassays such as ELISA, Western blot, and lateral flow tests for sensitive and specific detection of viral antigens. Supports development of therapeutic antibodies and vaccine efficacy studies by binding selectively to the RBD region involved in host cell entry.