Human metapneumovirus (hMPV) is a clinically significant respiratory pathogen responsible for severe infections in young children, the elderly, and immunocompromised individuals. The nucleoprotein (NP) is a highly conserved and abundantly expressed structural protein that encapsidates viral RNA into ribonucleoprotein complexes, a process essential for viral replication, transcription, and virion assembly. Unlike the more variable F and G glycoproteins, hMPV-NP exhibits strong antigenic conservation, making it an ideal target for antibody-based diagnostics and biomarker investigations. Catalina’s high-quality hMPV NP antibodies provide sensitive and reliable detection of viral NP in infected samples, supporting advanced research in respiratory virus biology, molecular virology, and immunopathogenesis.