The outbreaks of the infectious disease COVID-19 caused by SARS-CoV-2 seriously threatened the life of humans. A rapid, reliable and specific detection method was urgently needed. Herein, we reported a contamination-free visual detection method for SARS-CoV-2 with LAMP and CRISPR/Cas12a technology. CRISPR/Cas12a reagents were pre-added on the inner wall of the tube lid. After LAMP reaction, CRISPR/Cas12a reagents were flowed into the tube and mixed with amplicon solution by hand shaking, which can effectively avoid possible amplicon formed aerosol contamination caused by re-opening the lid after amplification. CRISPR/Cas12a can highly specific recognize target sequence and discriminately cleave single strand DNA probes (5′-6FAM 3′-BHQ1). With smart phone and portable 3D printing instrument, the produced fluorescence can be seen by naked eyes without any dedicated instruments, which is promising in the point-of-care detection. The whole amplification and detection process could be completed within 40 min with high sensitivity of 20 copies RNA of SARS-CoV-2. This reaction had high specificity and could avoid cross-reactivity with other common viruses such as influenza virus. For 7 positive and 3 negative respiratory swab samples provided by Zhejiang Provincial Center for Disease Control and Prevention, our detection results had 100% positive agreement and 100% negative agreement, which demonstrated the accuracy and application prospect of this method.

由SARS-CoV-2引起的传染病COVID-19的爆发严重威胁着人类的生命。迫切需要一种快速、可靠、特异的检测方法。在此，我们报道了一种利用 LAMP 和 CRISPR/Cas12a 技术对 SARS-CoV-2 无污染的视觉检测方法。管盖内壁预先添加了CRISPR/Cas12a试剂。 LAMP反应后，CRISPR/Cas12a试剂流入管内，用手摇动与扩增子溶液混合，可有效避免扩增后重新打开盖子可能造成的扩增子形成气溶胶污染。 CRISPR/Cas12a 可以高度特异性地识别目标序列并有区别地切割单链 DNA 探针 (5'-6FAM 3'-BHQ1)。通过智能手机和便携式3D打印仪器，无需任何专用仪器，肉眼即可看到产生的荧光，这在即时检测中具有广阔的前景。整个扩增和检测过程可在 40 分钟内完成，20 拷贝 SARS-CoV-2 RNA 的灵敏度很高。该反应特异性高，可避免与流感病毒等其他常见病毒发生交叉反应。对于浙江省疾病预防控制中心提供的7份阳性和3份阴性呼吸道拭子样本，我们的检测结果阳性一致性为100%，阴性一致性为100%，证明了该方法的准确性和应用前景。