11种灭活型样本保存液对病毒核酸保护效果的比较

Comparison of 11 Inactivated Sample-Preservation Solutions for Protection of Viral Nucleic Acids from Degradation

收集11种不同厂家的灭活型样本保存液,将甲型流感病毒加入保存液和生理盐水中,在4℃、25℃和37℃条件下保存0 h、2 h、4 h、6 h和24 h后,分别提取各组的病毒核酸,并通过逆转录实时荧光PCR检测病毒载量变化,以探究不同样本保存液对病毒核酸保护效果是否存在差异。结果发现不同样本保存液中的病毒载量随保存时间和温度变化存在显著差异。据此可将11种灭活型样本保存液的保存效果分为四类:(1)优秀产品:在任一温度(4℃、25℃、37℃)条件下,即使保存24h时病毒核酸都未发生明显降解,占比27.2%(3/11);(2)良好产品:低温(4℃)和室温(25℃)情况下核酸未出现降解,但在高温(37℃)条件下6 h后保存效果明显下降,占比27.2%(3/11);(3)合格产品:低温(4℃)条件下对病毒核酸具有较好的保护效果,但在室温(25℃)和高温(37℃)情况下随保存时间延长其保护效果显著下降,占比18.1%(2/11);(4)不合格产品:任一保存条件下对病毒核酸的保护效果都较差,甚至加入病毒后立即导致病毒核酸发生快速降解,占比27.2%(3/11)。以上结果说明不同厂家样本保存液对病毒核酸的保护效果存在显著差异,可能会导致病毒核酸检测出现假阴性结果。因此,需重点加强对样本保存液的质量监管,以有效保障病毒核酸检测,尤其是新冠核酸检测质量,以更好地做好疫情防控工作。

Inactivated sample-preservation solutions(SPSs) from 11 manufacturers were collected. Influenza A virus was added to each SPS and saline. Viral nucleic acids was extracted from each group after being storage at 4 ° C, 25 ° C and 37 ° C for 0, 2, 4, 6 and 24 h. Changes in viral loads were detected by real-time reverse transcription fluorescence polymerase chain reaction to identify differences in the protection of VNAs in different SPSs. We discovered that the viral load in different SPSs varied significantly with the preservation time and temperature. The 11 inactivated SPSs could be classified into four categories. The first category was “excellent products”(VNAs were not degraded significantly at any temperature(4°C, 25°C, 37°C) even after storage for 24 h) and accounted for 27.2%(3/11). The second category was “good products”(no degradation of VNAs occurred at low temperature(4° C) and room temperature(25° C), but the preservation effect decreased significantly after 6 h at high temperature(37°C)), and accounted for 27.2%(3/11). The third category was “qualified products”(the protection of VNAs was good at low temperature(4°C), but decreased significantly with an extension of storage time at room temperature(25°C) and high temperature(37°C)) and accounted for 18.1%(2/11). The fourth category was “substandard products”(protection of VNAs was poor under either storage condition, and even caused rapid degradation of VNAs immediately after the addition of virus) and accounted for 27.2%(3/11). Our results indicated a significant difference in the effect of SPSs from different manufacturers to protect VNAs from degradation, which could lead to false-negative results in VNA testing.Therefore, strengthening the quality control of SPSs must be done to guarantee the quality of VNA testing for better prevention and control of epidemics.