Coronavirus N protein is required for coronavirus RNA synthesis, and has RNA chaperone activity that may beinvolved in template switch. Nucleocapsid protein is a most abundant protein of coronavirus. N protein packagesthe positive strand viral genome RNA into a helical ribonucleocapsid (RNP) and plays a fundamental role duringvirion assembly through its interactions with the viral genome and membrane protein M. Plays an important rolein enhancing the efficiency of subgenomic viral RNA transcription as well as viral replication. Because of theconservation of N protein sequence and its strong immunogenicity, the N protein of coronavirus is chosen as adiagnostic tool.