Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, California 91125, United States.
Division of Engineering & Applied Science, California Institute of Technology, Pasadena, California 91125, United States.
ACS Infect Dis. 2023 Mar 10;9(3):450-458. doi: 10.1021/acsinfecdis.2c00472. Epub 2023 Feb 3.
The lateral flow assay format enables rapid, instrument-free, at-home testing for SARS-CoV-2. Due to the absence of signal amplification, this simplicity comes at a cost in sensitivity. Here, we enhance sensitivity by developing an amplified lateral flow assay that incorporates isothermal, enzyme-free signal amplification based on the mechanism of hybridization chain reaction (HCR). The simplicity of the user experience is maintained using a disposable 3-channel lateral flow device to automatically deliver reagents to the test region in three successive stages without user interaction. To perform a test, the user loads the sample, closes the device, and reads the result by eye after 60 min. Detecting gamma-irradiated SARS-CoV-2 virions in a mixture of saliva and extraction buffer, the current amplified HCR lateral flow assay achieves a limit of detection of 200 copies/μL using available antibodies to target the SARS-CoV-2 nucleocapsid protein. By comparison, five commercial unamplified lateral flow assays that use proprietary antibodies exhibit limits of detection of 500 copies/μL, 1000 copies/μL, 2000 copies/μL, 2000 copies/μL, and 20,000 copies/μL. By swapping out antibody probes to target different pathogens, amplified HCR lateral flow assays offer a platform for simple, rapid, and sensitive at-home testing for infectious diseases. As an alternative to viral protein detection, we further introduce an HCR lateral flow assay for viral RNA detection.
侧向流动分析方法可实现 SARS-CoV-2 的快速、无仪器、家庭式检测。由于缺乏信号放大，这种简单性是以灵敏度为代价的。在这里，我们通过开发一种基于杂交链式反应（HCR）机制的、具有等温、无酶信号放大功能的放大侧向流动分析方法来提高灵敏度。通过使用一次性 3 通道侧向流动设备，在无需用户交互的情况下，分三个连续阶段自动将试剂递送到测试区域，从而保持用户体验的简单性。要进行测试，用户加载样本，关闭设备，然后在 60 分钟后通过肉眼读取结果。在唾液和提取缓冲液混合物中检测伽马辐照的 SARS-CoV-2 病毒粒子时，当前的放大 HCR 侧向流动分析方法使用针对 SARS-CoV-2 核衣壳蛋白的现有抗体，可实现 200 拷贝/μL 的检测限。相比之下，使用专有抗体的五个商业未放大侧向流动分析方法的检测限分别为 500 拷贝/μL、1000 拷贝/μL、2000 拷贝/μL、2000 拷贝/μL 和 20,000 拷贝/μL。通过更换针对不同病原体的抗体探针，放大 HCR 侧向流动分析方法为传染病的简单、快速和敏感的家庭式检测提供了一个平台。作为病毒蛋白检测的替代方法，我们进一步引入了用于病毒 RNA 检测的 HCR 侧向流动分析方法。
