An international collaborative study to establish a World Health Organization international standard for hepatitis B virus DNA nucleic acid amplification techniques

摘要: Background and objectives Twenty-two laboratories from nine countries participated in an international collaborative study to establish a World Health Organization (WHO) standard for hepatitis B virus (HBV) DNA nucleic acid amplification techniques (NAT). Materials methods Three samples, AA, BB (both of which were lyophilized) CC (which was liquid preparation), analysed using several different NAT assays. The mean HBV content each sample determined the study. Results Despite range assays (commercial in-house) used by participants, there good agreement among overall ‘equivalents’/ml obtained assays, except one laboratory (laboratory 4). variation estimates log10‘equivalents’/ml 1·75–1·25 three samples if results 4 excluded. all 6·42 6·30 5·03 (exclusion made little difference). difference titres between two lyophilized (AA BB) not statistically significant but titre frozen (CC) significantly lower. Material AA (code 97/746) accepted as first WHO assigned potency 106 units (IU)/ml. Conclusions The (genome equivalents/ml) preparations This enabled establishment standard, 97/746,