ONI-CoV2RNA: A single step imaging-based assay for direct detection of SARS-CoV-2 RNA

点击翻译按钮获取中文摘要

Diagnostic testing for SARS-CoV2 is at the centre of the public health response to the COVID-19 pandemic, facilitating the isolation of asymptomatic cases thereby suppressing community transmission. COVID-19 testing is becoming ever more widespread as economic and recreational activities resume, for example, a negative test result is now required to travel to many international destinations. Two methods account for almost all SARS-CoV-2 diagnostic tests: RT-PCR and lateral flow antigen tests. RT-PCR tests provide high sensitivity but are performed in centralised facilities that depend on complex delivery networks, take several hours to process and have slow turnaround times (~24 h). Lateral flow tests are performed by the patient so the result is returned quickly (30 min), however, the test is less sensitive, catching only 60% of cases that were positive by RT-PCR (Cochrane review, 2021). RT-PCR and lateral flow tests require a nasopharyngeal swab, which is uncomfortable to perform and can give inconsistent results if not collected by a trained professional. ONI is developing a novel method to detect SARS-CoV-2 and other respiratory viruses in under 10 minutes by removing time-consuming and costly sample preparation steps, using widely available reagents and making sample analysis automated, faster and safer.Our single-step virus detection assay will allow direct detection and differentiation of SARS-CoV-2 and other viruses in saliva without the need for a nasopharyngeal swab. The assay will run on ONI's new imaging device, with a unique desktop-format and easy-to-use workflow designed specifically for this assay. Together with partners at Imperial College London we will perform side-by-side validation with existing tests on COVID-19 clinical swab samples and assess its ease of use through the London IVD Cooperative. We will then optimise the instrument’s usability with partners at Medicines Discovery Catapult (MDC)-Lighthouse Labs so that the device can be easily operated by non-specialists. Our test will remove the need for high-containment facilities and specialised personnel with automated assay operation, facilitating its use in de-centralised clinical and non-clinical settings. We will engage regulatory bodies to support testing at airports and companies, where our compact and rapid platform will allow detection of SARS-CoV-2 and other respiratory viruses in asymptomatic carriers in a few minutes, helping reduce infection spread, minimising further economic losses and allowing control of future emerging viruses. The ONI-VirusDx assay has the potential to allow rapid, de-centralised single-step virus testing UK-wide.