采样管振荡及静置时间对新型冠状病毒核酸结果的影响

Objective To explore the influence of oscillation mode and standing time of sampling tubes of various specifications on the detection results of novel coronavirus nucleic acid. Methods In December, 2022, 552 novel coronavirus positive swabs simulating the same low viral load were prepared in the Gene Amplification Laboratory of Beihai Hospital of Traditional Chinese Medicine, and placed in various sampling tubes. Count the changes of CycleThreshold(Ct) values detected by two methods: instrument shaking for 5 seconds and manual shaking for 5 seconds, and adding samples immediately after instrument shaking and standing for 15, 30 and 45 minutes. To analyze the influence of sampling tube size, oscillation mode and standing time on the efficiency and positive rate of nucleic acid screening in novel coronavirus. Results Manual oscillation mode has larger Ct value than instrument oscillation mode. Compared with the instrument and manual shaking for 5 seconds, the Ct values of ORF1 ab and N genes in the 10 : 1 and 20 : 1 mixed sampling tube groups increased gradually compared with the single sampling tube, and the difference was statistically significant(P<0.05). The false negative rate of 20 : 1 mixed sampling tube was 2.13% in the manual shaking test for 5 seconds. There was a significant difference in Ct values between 10 : 1 and 20 : 1 mixed sampling tubes standing for 30 and 45 minutes and immediately adding samples(P<0.05). The positive rate of novel coronavirus nucleic acid was 98.9%, and the false negative rate was 1.1%. Conclusion Using 10 : 1 mixed sampling tube and instrument oscillation mode and completing sample addition within 30 minutes can improve the efficiency and positive rate of nucleic acid screening in novel coronavirus and avoid false negatives.