The SARS-CoV-2 nucleocapsid (N) protein is a highly conserved, ~46 kDa RNA-binding structural protein essential for viral genome packaging, replication, and assembly. As one of the most abundant and immunogenic viral antigens, it elicits strong antibody and T-cell responses during COVID-19 infection. Due to its high expression and stability, the N protein is widely used as a biomarker for viral detection, serological testing, and immune monitoring across SARS-CoV-2 variants. Catalina offers rigorously validated SARS-CoV-2 Nucleocapsid antibodies that provide exceptional sensitivity and specificity for COVID-19 diagnostics, immunology research, vaccine development, and antiviral screening.