Abstract:

Objective To compare the consistency rate,repeatability and detection limit of magnetic bead adsorption method and sample releasing agent method in the nucleic acid extraction of severe acute respiratory syndrome coronavirus 2（SARS-CoV-2）,so as to optimize the extraction method of nucleic acid with high extraction efficiency,short time consuming and low cost. Methods Totally,3 commercial nucleic acid extraction reagents for 2 methods of nucleic acid extraction were used to extract RNA from negative samples,positive samples and SARS-CoV-2 standard samples with different dilution（20-28）,and real-time fluorescence reverse transcription-polymerase chain reaction（RT-PCR） was performed. Ct value was used to evaluate the performance of different nucleic acid extraction methods. Results The consistency rate of negative and positive samples of 3 nucleic acid extraction reagents was 100%. The coefficient of variation（CV） of magnetic bead adsorption method was lower than those of sample releasing agent method（CV 0.89%-1.58%）,sample releasing agent A（CV 1.62%-4.90%） and sample releasing agent B（CV 0.83%-2.73%）. The detection limit of magnetic bead adsorption method and sample releasing agent B was 156.3 copies/mL,and that of sample releasing agent A was 625.0 copies/mL. Conclusions The magnetic bead adsorption method of nucleic acid extraction is efficient and reproducible,which is suitable for the centralized operation of a large number of samples.

Key words: Severe acute respiratory syndrome coronavirus 2, Nucleic acid detection, Nucleic acid extraction, Real-time fluorescence reverse transcription-polymerase chain reaction