Fei Xiang, Xiaorong Wang, Xinliang He, et al. - As the corona virus disease 2019 (COVID-19) caused by the corona virus 2 (SARS-CoV-2) has been rapidly spreading nationwide and abroad, researchers sought to develop a serologic test to recognize antibody dynamics and response to SARS-CoV-2. Using an enzyme-linked immunosorbent assay (ELISA), they identified the antibodies against SARS-CoV-2 based on the recombinant nucleocapsid protein of SARS-CoV-2 in cases with confirmed or suspected COVID-19 at 3-40 days after symptom onset. Nucleic acid testing for SARS-CoV-2 by RT-PCR is the gold standard for COVID-19 diagnosis. Observations revealed that as early as the 4th day after symptom onset, the seroconversion of specific IgM and IgG antibodies could be seen, indicating that detection of the antibodies against SARS-CoV-2 can be done in the middle and later stage of the illness. Both antibodies performed well in serodiagnosis for COVID-19 rely on great specificity. In the diagnosis of COVID-19, antibody identification may play a significant role as complement approach for viral nucleid acid assays.