A pair of SARS-CoV-2 nucleocapsid protein monoclonal antibodies shows high specificity and sensitivity for diagnosis.

• Seven monoclonal antibodies (mAbs) against SARS-CoV-2 nucleocapsid protein are produced, which can be applied in ELISA, WB, and IF assays. • A pair of mAbs, 2G11/bio-1C7, can detect SARS-CoV-2 nucleocapsid protein as low as 15 pg/well in the double sandwich ELISA. • The mAb, 2G11, shows 97.