The rapid development of global COVID-19 pandemic poses an unprecedented challenge to the safety and quality of laboratory diagnostic testing. Little is known about the laboratory surface areas and operation behaviors that may cause potential contamination in SARS-CoV-2 nucleic acid testing. This study aims to provide reference basis for the improvement of laboratory disinfection programs and personal operating protocols. In this study, we compared the qRT-PCR and ddPCR in detecting of residual virus that existed on the object surfaces from sample transportation and reception related facilities, testing related instruments, personal protective equipment and other facilities in nucleic acid testing laboratory. All samples were negative by qRT-PCR, in contrast, 13 of 61 samples were positive for SARS-CoV-2 by ddPCR. The areas with highest density of SARS-CoV-2 nucleic acid were the outer gloves of operator A (37.4 copies/cm²), followed by door handle of 4 °C refrigerator (26.25 copies/cm²), goggles of operator A (22.16 copies/cm²), outer cover of high speed centrifuge (19.95 copies/cm²), inner wall of high speed centrifuge (14.70 copies/cm²) and others. We found that all the positive objects were directly or indirectly contacted by the operator's gloved hands, suggesting that hands contact was the main transmission pathway that led to laboratory environmental contamination. In summary, ddPCR has an advantage over qRT-PCR in tracing laboratory contamination. We evaluated the risk areas and operation behaviors that may easily cause contamination, and provided recommendation for improving the laboratory disinfection programs and personal operating specifications.

全球 COVID-19 大流行的迅速发展对实验室诊断检测的安全性和质量提出了前所未有的挑战。对可能导致 SARS-CoV-2 核酸检测潜在污染的实验室表面积和操作行为知之甚少。本研究旨在为完善实验室消毒方案和个人操作规程提供参考依据。在本研究中，我们比较了 qRT-PCR 和 ddPCR 在核酸检测实验室样本运输和接收相关设施、检测相关仪器、个人防护设备等设施中检测物体表面存在的残留病毒。所有样本 qRT-PCR 均为阴性，相比之下，61 个样本中有 13 个样本通过 ddPCR 对 SARS-CoV-2 呈阳性。²）、4℃冰箱门把手（26.25份/cm ²）、操作员A护目镜（22.16份/cm ²）、高速离心机外壳（19.95份/cm ²）、高速离心机内壁高速离心机（14.70份/cm ²） 和别的。我们发现，所有阳性物体均直接或间接与操作者戴手套的手接触，提示手接触是导致实验室环境污染的主要传播途径。总之，ddPCR 在追踪实验室污染方面优于 qRT-PCR。我们评估了容易造成污染的风险区域和操作行为，并为改进实验室消毒方案和个人操作规范提出了建议。