A Portable Device for LAMP Based Detection of SARS-CoV-2

Abstract

This paper reports the design, development, and testing of a novel, yet simple and low-cost portable device for the rapid detection of SARS-CoV-2. The device performs loop mediated isothermal amplification (LAMP) and provides visually distinguishable images of the fluorescence emitted from the samples. The device utilises an aluminium block embedded with a cartridge heater for isothermal heating of the sample and a single-board computer and camera for fluorescence detection. The device demonstrates promising results within 20 min using clinically relevant starting concentrations of the synthetic template. Time-to-signal data for this device are considerably lower compared to standard quantitative Polymerase Chain Reaction(qPCR) machine (~10-20 min vs. >38 min) for 1 × 10² starting template copy number. The device in its fully optimized and characterized state can potentially be used as simple to operate, rapid, sensitive, and inexpensive platform for population screening as well as point-of-need severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) detection and patient management.

Keywords: loop-mediated isothermal amplification; portable device; severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2).

Figure 1

(a) Schematic of the experimental setup. (b) Photographs of fluorescence emitted from various samples upon performing the loop mediated isothermal amplification (LAMP).

Figure 2

(a) Amplification curves obtained for LAMP reactions carried out on conventional qPCR machine. (b) Corresponding melt peaks. For MERS-CoV and SARS-CoV controls see Section 2.1 for details. NTC = no-template control. (c) Variation of normalised fluorescent intensity of various samples with respect to time on performing the LAMP.

Figure 3

(a) Exploded view of the portable device. (b) Photograph of the portable device. (c) Screenshot of the graphical user interface.