Used in research and diagnostic applications to detect the spike protein's receptor-binding domain (RBD) of SARS-CoV-2. Helps in studying virus-antibody interactions, evaluating immune responses in infected or vaccinated individuals, and developing diagnostic assays for COVID-19. Also employed in neutralization studies to assess the effectiveness of antibodies in blocking viral entry into host cells. Suitable for use in ELISA, flow cytometry, and immunofluorescence techniques.