Detection of HBV-DNA in dried bloodstains on filter-paper

Objective To develop a method for hepatitis Bvirus(HBV)DNA detection in dried bloodstain samples.Methods Template DNA was extracted from a blood stainon filter-paper by Chelex-100 method and then was amplified by nested PCR with anoptmiized protocal.The sensitivity and specificity of the method were analyzed.The positive rate of the nested PCR-based method was compared with that of ELISA method with McNemar's test.Results Specific HBV-DNA fragment of 193 bp was amplified with nested PCR in combination with Chelex-100 method from dried blood stain samples of 3×3 mm² size.The lowest detection lmiit of the test was 5 copies of HBV-DNA per L.McNemar's test showed that the difference in positiv erate between the two methods was not statistically significant(P=0.289 0).HBV test results showed a good concordance between the two methods(kappa=0.727).Conclusion The methode stablished is specific and sensitive for HBV-DNA detction with a little amount of drired blood sample.The method could beadopted in large scale molecular epidemiological studies and HBV screening before blood donation.