Determination of SARS antibody titer by ELISA method

Objective To develop a determination method for Severe Acute Respiratory Syndrome (SARS) Coronavirus antibody titer based on the ELISA method.Methods Results Testing 249 negative and 47 positive samples,all positive samples and one of 249 negative samples showed positive results.Thus the specificity is more than 99.7%.The calibration curve is linear over the titer range from 0.5U/ml to 8.0U/ml with r0.98.Recovery ranges from 85% to 110%.And accuracy of within-day is less than 2%(α=0.05,n=5).While accuracy of inter-person is less than 18%(α=0.05,n=5).Conclusion The method complies with the requirement for immunoassays and can be adapt to determine the SARS antibody titer in human plasma or human SARS Immunoglobulin products.