Abstract High-quality recombinant antigens and reliable and accurate SARS-CoV-2 serological assays are urgently needed for surveillance and for defining the immune mechanisms of viral pathogenesis, viral clearance, and protection against reinfection. Core B of the UNC SARS-CoV-2 Serological Sciences Center of Excellence will apply state-of-the-art strategies to establish methods for the production of milligram quantities of homogeneous recombinant spike protein CoV antigens with versatile tags and site-specific labels and use these antigens to develop sensitive and reliable singleplex and multiplex Ab detection assays. Core B will interact and support all the projects driven by the center and collaborators' by providing recombinant antigens and serological assays to characterize the serum antibody response, elucidate Fc effector functional profiles, and isolate and sequence antigen-specific immunoglobulin gene repertoire.