Abstract: Objective Nucleic acid tests were performed in the blood donors and compared with the Results of ELISA double negative and single reagent reactive in HBsAg,Anti-HCV and Anti-HIV so as to provide a basis for distinguishing the false positive blood donors. Methods Two ELISA reagents were used to detect seral HBsAg,HCV and HIV in the donors,and 8 specimens of ELISA negative and single reagent positive samples were subjected to DNAs detections. All DNAs positive samples were identified. Results In 31 065 blood samples,30 254 cases were found to be negative with double ELISA,and 241 cases were positive with single reagent examination,among them 180 cases were detected with imported kits and 61 with domestic reagents. A significant difference was seen in different reagents. DNAs detection showed 54 positive samples including 46 HBV,3 HCV,and 5 HIV. Identification tests revealed 39 positive HBV,among them 37 and 2 cases were found from ELISA negative and single reagent positive samples,respectively. Neither HCV nor HIV was discovered and total positive rate was 72.2%.Conclusion ELISA single reagent reactive result gives rise to a high false positivity while DNAs examination may improve the efficacy of virus diagnosis. Complementary examinations are recommended so as to induce the risk of blood transfusion of infectious diseases.

Key words: Single reagent reactive, Nucleic acid detection, Identification tests