自配新型冠状病毒核酸弱阳性质控品的评价

An Evaluation of Self-Formulated 2019-nCoV NucleicAcid Weakly Positive Quality Control

目的评价不同基质配制新型冠状病毒假病毒颗粒制备弱阳性质控品的可行性。方法用无RNA酶水、样本保存液和生理盐水对一定浓度的假病毒颗粒配制至检测限的2.5倍,评价其均一性、反复冻融、4℃存放、常温存放、-30℃冻存的稳定性。结果生理盐水为基质的弱阳性质控品均一性差,不适合作为质控品基质。其余两种基质的均一性良好,ORF1ab基因的两组间比较Ct值差异均有统计学意义;反复冻融10次、4℃存放7 d、-30℃冻存8周的稳定性良好;无RNA酶水作为基质时常温存放24h稳定性良好,样本保存液作为基质时,12 h后N基因稳定性降低,16 h ORF1ab基因稳定性降低。结论以无RNA酶水作为基质制成的弱阳性质控品稳定性优于样本保存液,可以在实验室中应用。

Objective To evaluate the feasibility of preparing weak-positive quality control substance with different matrix dilution of 2019-nCoV pseudovirions.Methods Pseudovirions with a certain concentration were diluted to 2.5 times of the detection limit with RNA-free water,sample preservation solution or normal saline.The homogeneity,repeated freeze-thaw storage,storage stability at 4℃,normal temperature and-30℃were evaluated.Results Weak positive quality control products with normal saline as substrate had a poor homogeneity,so this group was excluded.The other two matrices showed a good homogeneity,and the CT values of ORF1ab gene showed a difference between the two groups.Freeze-thaw 10 times,stored at 4℃for 7 days and frozen at-30℃for 8 weeks have a good stability.When the RNA-free enzyme water was used as the substrate,the stability was good at room temperature for 24 hours,while the stability of N gene decreased after 12 hours and that of ORF1ab gene decreased after 16 hours when the sample storage solution was used as the substrate.Conclusion The stability of weakly positive quality control product made from RNA-free enzyme water is better than that of sample preservation solution and can be used in laboratory.