The novel coronavirus SARS-CoV-2 is the causative agent of the acute respiratory disease COVID-19, which has become a global concern due to its rapid spread. Laboratory work with SARS-CoV-2 in a laboratory setting was rated to biosafety level 3 (BSL-3) biocontainment level. However, certain research applications in particular in molecular biology require incomplete denaturation of the proteins, which might cause safety issues handling contaminated samples. In this study, we evaluated lysis buffers that are commonly used in molecular biological laboratories for their ability to inactivate SARS-CoV-2. In addition, viral stability in cell culture media at 4 °C and on display glass and plastic surfaces used in laboratory environment was analyzed. Furthermore, we evaluated chemical and non-chemical inactivation methods including heat inactivation, UV-C light, addition of ethanol, acetone-methanol, and PFA, which might be used as a subsequent inactivation step in the case of insufficient inactivation. We infected susceptible Caco-2 and Vero cells with pre-treated SARS-CoV-2 and determined the tissue culture infection dose 50 (TCID₅₀) using crystal violet staining and microscopy. In addition, lysates of infected cells and virus containing supernatant were subjected to RT-qPCR analysis. We have found that guanidine thiocyanate and most of the tested detergent containing lysis buffers were effective in inactivation of SARS-CoV-2, however, the M-PER lysis buffer containing a proprietary detergent failed to inactivate the virus. In conclusion, careful evaluation of the used inactivation methods is required especially for non-denaturing buffers. Additional inactivation steps might be necessary before removal of lysed viral samples from BSL-3.

新型冠状病毒 SARS-CoV-2 是急性呼吸道疾病 COVID-19 的病原体，由于其迅速传播，已成为全球关注的问题。在实验室环境中使用 SARS-CoV-2 进行的实验室工作被评为生物安全 3 级 (BSL-3) 生物防护级别。然而，某些研究应用，特别是分子生物学，需要蛋白质不完全变性，这可能会导致处理受污染样品的安全问题。在本研究中，我们评估了分子生物学实验室常用的裂解缓冲液灭活 SARS-CoV-2 的能力。此外，还分析了 4 °C 下细胞培养基和实验室环境中使用的展示玻璃和塑料表面中的病毒稳定性。此外，我们评估了化学和非化学灭活方法，包括热灭活、UV-C 光，添加乙醇、丙酮-甲醇和 PFA，在失活不足的情况下，可将其用作后续的失活步骤。我们用预处理过的 SARS-CoV-2 感染易感的 Caco-2 和 Vero 细胞，并确定了组织培养感染剂量 50（TCID₅₀ ) 使用结晶紫染色和显微镜检查。此外，对感染细胞的裂解物和含有病毒的上清液进行 RT-qPCR 分析。我们发现硫氰酸胍和大多数测试的含有裂解缓冲液的去污剂可有效灭活 SARS-CoV-2，然而，含有专有去污剂的 M-PER 裂解缓冲液未能灭活病毒。总之，需要仔细评估所使用的灭活方法，尤其是对于非变性缓冲液。在从 BSL-3 中去除裂解的病毒样本之前，可能需要额外的灭活步骤。