[Detection of SARS-associated coronavirus N protein by time-resolved fluoroimmunoassay].

Wang, Lei; Wu, Ying-Song; Tang, Yong-Ping; Li, Ming

OBJECTIVE To develop a method for quantitative detection of severe acute respiratory syndrome (SARS)-associated coronavirus (SARS-CoV) N protein by timed-resolved fluoroimmunoassay (TRFIA). METHODS Using a monoclonal antibody (mAb) against SARS-CoV N protein, screened by SARS-CoV N protein and matching experiment, a method for quantitative detection of SARS-CoV N protein by TRFIA was established on the basis of double sandwich enzyme-linked immunosorbent assay (ELISA) and evaluated against the ELISA kit. RESULT The measurement range of the assay was 0.02-150 ng/ml with a sensitivity of 0.02 ng/ml, the coefficient of variability within runs of 3.3%;-6.2%;, and coefficient of variability between days of 5.3%;-9.6%;. The results of detection were consistent between ELISA and TRFIA. CONCLUSION TRFIA is a new, sensitive and specific immunoassay for detecting SARS N protein with potential value in clinical applications.