Harmony COVID-19: a ready-to-use kit, low-cost detector, and smartphone app for point-of-care SARS-CoV-2 RNA detection

Abstract

RNA amplification tests sensitively detect SARS-CoV-2 infection, but their complexity and cost are prohibitive for expanding COVID-19 testing. We developed Harmony COVID-19, a point-of-care test using inexpensive consumables, ready-to-use reagents, and a simple device accommodating up to 4 samples simultaneously. Our ready-to-use, 4-plex reverse-transcription, loop-mediated isothermal amplification (RT-LAMP) can detect down to 0.38 SARS-CoV-2 RNA copies/μL and can report in 17 min for high viral load samples (5,000 copies/μL). Harmony detected 97% or 83% of contrived samples with ≥0.5 viral particles/μL in nasal matrix or saliva, respectively. Evaluation in clinical nasal specimens in viral transport media (VTM, n=101) showed 100% detection of RNA extracted from specimens with ≥0.5 SARS-CoV-2 RNA copies/μL, with 100% specificity in specimens positive for other respiratory pathogens. VTM is non-ideal for Harmony system, yet extraction-free analysis of VTM specimens (n=29) had 95% success in specimens with ≥1 RNA copies/μL. Usability testing performed first-time by healthcare workers showed 95% accuracy

Isothermal Amplification with a Target-Mimicking Internal Control and Quantitative Lateral Flow Readout for Rapid HIV Viral Load Testing in Low-Resource Settings

“…A more important concern for reagent storage is ease of use; ideally, all oligos should be stored with the lyophilized pellet to reduce assay setup complexity, , and any liquid reagents should be combined into a single, small volume that is easy to add to the pellet (e.g., with a single-use exact volume transfer pipette). We have observed favorable performance and user feedback with a similar workflow conducted by nontrained first-time users or healthcare workers for HIV , or SARS-CoV-2 assays . These changes have the added benefit of minimizing reagent volume, which allows for a larger sample input volume.…”

“…We have observed favorable performance and user feedback with a similar workflow conducted by nontrained first-time users or healthcare workers for HIV 34,36 or SARS-CoV-2 assays. 37 These changes have the added benefit of minimizing reagent volume, which allows for a larger sample input volume. Sample preparation must also be addressed in a clinical implementation; a blood sample for VL testing must first be collected, filtered or otherwise processed to remove cellular components, and purified to remove ribonucleases and other inhibitors and concentrate viral RNA.…”

A handheld intelligent single-molecule binary bioelectronic system for fast and reliable immunometric point-of-care testing

“…These approaches have been proven capable of assaying SARS-CoV-2 viral RNA in nasal, nasopharyngeal, or throat swabs at an LOD of 10 to 100 copies per milliliter (5). Similar figures of merit have also been demonstrated in POC tests such as the CRISPR-Cas-based smartphone-read saliva tests (9) or, to a less high-performance level, in the RT-LAMP Harmony COVID-19 (10). While being quantitative with a wide dynamic range, molecular-based POC tests still have not fully addressed key aspects such as portability, simplicity of use, and independence from resource/ infrastructure.…”

Visual Detection of COVID-19 from Materials Aspect

“…Various smartphone-based visual detection techniques, such as optical biosensors, electrochemical biosensors, surface acoustic wave biosensors have been developed [133,134]. In addition, the corresponding smartphone apps have also been developed to record, process and transmit the test data [135,136].…”