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. Commonly applied in ELISA, lateral flow assays, and immunofluorescence techniques to identify viral antigens. Supports development of therapeutic antibodies and diagnostic kits due to its high specificity for the spike RBD.