Saliva-Dry LAMP: A Rapid Near-Patient Detection System for SARS-CoV-2.

Abstract

The highly infectious nature of SARS-CoV-2 necessitates the use of widespread testing to control the spread of the virus. Presently, the standard molecular testing method (reverse transcriptase-polymerase chain reaction, RT-PCR) is restricted to the laboratory, time-consuming, and costly. This increases the turnaround time for getting test results. The study sought to develop a rapid, near-patient saliva-based test for COVID-19 with similar accuracy to that of standard RT-PCR tests. A lyophilized dual-target reverse transcription-loop-mediated isothermal amplification (RT-LAMP) test with fluorometric detection by the naked eye. The assay relies on dry reagents that are room temperature stable. A device containing a centrifuge, heat block, and blue LED light system was manufactured to reduce the cost of performing the assay. This test has a limit of detection of 1 copy/µL and achieved positive percent agreement of 100% [95% CI 88.43% to 100.0%] and negative percent agreement of 96.7% [95% CI 82.78% to 99.92%] on saliva. Saliva-Dry LAMP can be completed in 105 minutes. Precision, cross-reactivity, and interfering substances analysis met international regulatory standards. The combination of ease of sample collection, dry reagents, visual detection, low capital equipment cost, and excellent analytical sensitivity make Saliva-Dry LAMP particularly useful for resource-limited settings.

Digital Droplet PCR to Track SARS-CoV-2 Outbreak in a Hospital Transitional Care Unit

“…A total of 97 environmental samples were taken throughout the unit by using floc swabs to thoroughly swab each area of interest the same number of times, placing into Dulbecco's Modified Eagle Medium (DMEM) and freezing at -80°C before being extracted for analysis. 5 …”

Portable and Label-Free Quantitative Loop-Mediated Isothermal Amplification (LF-qLamp) for Reliable COVID-19 Diagnostics in Three Minutes of Reaction Time: Arduino-Based Detection System Assisted by a pH Microelectrode

“…One potential alternative to RT-qPCR could be loop-mediated isothermal amplification (LAMP for short), which has been extensively studied in recent reports as a cost-effective diagnostic system in the context of the current COVID-19 pandemic [7][8][9][10][11][12][13][14][15]. Overall, these reports have documented that LAMP-based methods have comparable sensitivity and specificity to that of RT-qPCR.…”

Portable and label-free quantitative Loop-mediated Isothermal Amplification (qLAMP) for reliable COVID-19 diagnostics in 3 minutes: An Arduino-based detection system assisted by a pH microelectrode

“…One potential alternative to RT-qPCR could be Loop-mediated Isothermal Amplification (LAMP), which has been extensively studied in recent reports as a cost-effective diagnostic system in the context of the current COVID-19 pandemic [8][9][10][11][12][13][14][15][16]. Overall, these reports have documented that LAMP-based methods have comparable sensitivity and specificity to that of RT-qPCR.…”