The COVID-19 pandemic has exposed the dependence of diagnostic laboratories on a handful of large corporations with market monopolies on the worldwide supply of reagents, consumables, and hardware for molecular diagnostics. Global shortages of key consumables for RT-qPCR detection of SARS-CoV-2 RNA have impaired the ability to run essential, routine diagnostic services. Here, we describe a workflow for rapid detection of SARS-CoV-2 RNA in upper respiratory samples including nasal swabs and saliva, utilizing low-cost equipment and readily accessible reagents. Using repurposed Creality3D Ender-3 three-dimensional (3D) printers, we built a semiautomated paramagnetic bead RNA extraction platform. The hardware for the system was built for $300 USD, and the material cost per reaction was $1 USD. Named the Ender VX500, instrument performance when paired with RT-qPCR for SARS-CoV-2 detection in nasal and saliva specimens was two virus copies per microliter. There was a high-performance agreement (assessed using 458 COVID-19 nasal swab specimens) with the Aptima SARS-CoV-2 assay run on the Hologic Panther, a commercial automated RNA extraction and detection platform. Inter- and intrainstrument precision was excellent (coefficients of variation (CoV) of 1.10 and 0.66–1.32%, respectively) across four instruments. The platform is scalable with throughput ranging from 23 specimens on a single instrument run by one user in 50 min to 364 specimens on four instruments run by four users in 190 min. Step-by-step instructions and protocols for building and running the Ender VX500 have been made available without restriction.

中文翻译：

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使用改造后的 3D 打印机进行 RNA 提取的高通量 COVID-19 分子诊断和基因组测序的无障碍平台

COVID-19 大流行暴露了诊断实验室对少数大公司的依赖，这些大公司在全球分子诊断试剂、耗材和硬件供应方面拥有市场垄断地位。全球用于 SARS-CoV-2 RNA RT-qPCR 检测的关键耗材短缺，削弱了运行基本常规诊断服务的能力。在这里，我们描述了利用低成本设备和易于获取的试剂快速检测上呼吸道样本（包括鼻拭子和唾液）中 SARS-CoV-2 RNA 的工作流程。使用改造后的Creality3D Ender-3三维 (3D) 打印机，我们构建了半自动顺磁珠 RNA 提取平台。该系统的硬件造价为 300 美元，每个反应的材料成本为 1 美元。名为Ender VX500 的仪器与 RT-qPCR 配合使用，检测鼻腔和唾液样本中的 SARS-CoV-2，其性能为每微升 2 个病毒拷贝。与在商业自动化 RNA 提取和检测平台 Hologic Panther 上运行的 Aptima SARS-CoV-2 检测达成了高性能协议（使用 458 个 COVID-19 鼻拭子样本进行评估）。四台仪器的仪器间和仪器内精度均非常出色（变异系数 (CoV) 分别为 1.10 和 0.66-1.32%）。该平台具有可扩展性，吞吐量范围从一名用户在 50 分钟内运行一台仪器上的 23 个样本到在 190 分钟内由四位用户运行四台仪器上的 364 个样本。用于构建和运行Ender VX500 的分步说明和协议已不受限制地提供。