The Influenza A virus nucleoprotein (NP) is a ~56 kDa RNA-binding protein essential for viral replication, genome packaging, and interaction with the viral polymerase complex (PB1, PB2, PA). NP also contains nuclear localization signals that coordinate nuclear import and export of viral ribonucleoproteins (RNPs). Unlike the variable surface antigens hemagglutinin (HA) and neuraminidase (NA), NP is highly conserved across influenza A subtypes, making influenza A NP antibodies valuable for broad detection, diagnostic immunoassays, and pan-influenza surveillance. NP is also under investigation as a universal influenza vaccine antigen. While anti-NP antibodies do not provide direct neutralization, they remain indispensable tools for influenza diagnostics, research, vaccine evaluation, and antiviral discovery. Catalina offers rigorously validated influenza A virus NP antibodies that deliver high sensitivity and specificity, ensuring accurate detection in diverse applications.