Department of Electrical and Computer Engineering, Duke University, Durham, NC, 27708, USA.
Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA.
Sci Rep. 2022 Apr 29;12(1):7043. doi: 10.1038/s41598-022-11144-5.
Access to fast and reliable nucleic acid testing continues to play a key role in controlling the COVID-19 pandemic, especially in the context of increased vaccine break-through risks due to new variants. We report a rapid, low-cost (~ 2 USD), simple-to-use nucleic acid test kit for self-administered at-home testing without lab instrumentation. The entire sample-to-answer workflow takes < 60 min, including noninvasive sample collection, one-step RNA preparation, reverse-transcription loop-mediated isothermal amplification (RT-LAMP) in a thermos, and direct visual inspection of a colorimetric test result. To facilitate long-term storage without cold-chain, a fast one-pot lyophilization protocol was developed to preserve all required biochemical reagents of the colorimetric RT-LAMP test in a single microtube. Notably, the lyophilized RT-LAMP assay demonstrated reduced false positives as well as enhanced tolerance to a wider range of incubation temperatures compared to solution-based RT-LAMP reactions. We validated our RT-LAMP assay using simulated infected samples, and detected a panel of SARS-CoV-2 variants with successful detection of all variants that were available to us at the time. With a simple change of the primer set, our lyophilized RT-LAMP home test can be easily adapted as a low-cost surveillance platform for other pathogens and infectious diseases of global public health importance.
快速、可靠的核酸检测仍然是控制 COVID-19 大流行的关键，尤其是在新变种导致疫苗突破性风险增加的情况下。我们报告了一种快速、低成本（约 2 美元）、易于使用的核酸检测试剂盒，可用于在家中进行自我检测，无需实验室仪器。整个样本到答案的工作流程耗时不到 60 分钟，包括非侵入性样本采集、一步式 RNA 制备、在热室中进行逆转录环介导等温扩增（RT-LAMP）以及直接目视检查比色测试结果。为了便于长期储存而无需冷链，开发了快速的一步冻干方案，将比色 RT-LAMP 测试所需的所有生化试剂保存在一个微管中。值得注意的是，与基于溶液的 RT-LAMP 反应相比，冻干的 RT-LAMP 检测法显示出降低的假阳性率以及对更宽范围的孵育温度的更高耐受性。我们使用模拟感染样本对我们的 RT-LAMP 检测进行了验证，并成功检测到了我们当时拥有的所有 SARS-CoV-2 变体。只需简单更改引物组，我们的冻干 RT-LAMP 家庭检测就可以轻松适应其他病原体和具有全球公共卫生重要性的传染病的低成本监测平台。
