Abstract: ObjectiveTo explore the agreement between the testing results of reactive samples by ELISA for HBsAg and HBV DNA by PCR,so as that a more accurate testing may be provided for the donors. MethodsPCR was apply to the reactive samples from volunteer donors who had been tested by ELISA for HBsAg to make a comparison between the results.ResultsBy employing two ELISA reagents, 698 samples are tested to be reacted positively in the total of 122,675. Among the 698 samples, there are 382 have been equally detected positive by the two ELISA reagents. 203 cases were found PCR positive, account for 29.08%. 179 cases are PCR negative, account for 25.64%. Among the 204 positive samples tested by one ELISA reagent, 8 cases are found PCR positive, account for 1.15%; 196 negative cases existed, account for 28.08%. By employing two ELISA reagents, 5 samples were within the gray area. None of them were positive for PCR, account for 0%; while 5 negative were observed, account for 0.72%; by employing one single ELISA reagent, 107 cases were within the gray area and 5 cases were PCR positive, comprise 0.72%; 102 are negative, account for 14.61 %. ConclusionIn the HBsAg blood screening, different ELISIA reagents showed different degrees of sensitivity and specificity. If double reagents are applied, the positive reaction results are more likely to be consistent with the results from HBV DNA. A few cases within gray area are also identical with them, but the development of HBV DNA should be closely observed and followed-up.

Key words: HBsAg, ELISA, PCR, Gray, area