RESUMO
@#ObjectiveTo develop a national standard for genomic titer determination of recombinant type 5 adeno-associated virus(rAAV5).MethodsThe rAAV5-GFP stock solution prepared by the three-plasmid system was identified and verified for the appearance,pH,sterility,genomic titer,purity and infection titer according to the relevant requirements of Chinese Pharmacopoeia(Volume Ⅲ,2020 edition),which was diluted and subpackaged to prepare candidate standards according to the results;The stability of candidate standards was investigated by thermal acceleration test;Three laboratories were organized to collaboratively calibrate the candidate standards using droplet digital PCR(ddPCR).ResultsAll the detection indexes of the candidate standard and the stock solution met the relevant requirements;The genomic titer showed no significant decrease at 25,4,-20,-40,-80 ℃ for 1,3,4,6 months;Through collaborative calibration by three laboratories,the candidate standard was assigned a value of 2. 56 × 10(12)copies/mL,and the 95% confidence interval was 2. 48 ×10(12)copies/mL,and the 95% confidence interval was 2. 48 ×10(12)copies/mL ～ 2. 64 × 10(12)copies/mL ～ 2. 64 × 10(12)copies/mL.ConclusionThe developed national standard for the determination of rAAV5 genomic titer had good stability and might be used for the quality evaluation of rAAV5 related products.