A low-cost, portable, dual-function readout device for amplification-based point-of-need diagnostics

Abstract

ABSTRACT Amplification-based diagnostics has been widely used in plant disease diagnostics due to its sensitivity, rapidness, and flexibility. The modules to interpret amplification results rapidly, reliably, and easily in resource-limited settings (e.g., field-based environments) are in high demand. Therefore, we have designed and developed a simple, low-cost, easy-to-perform, and portable device named Dr. Diagnose to aid accurate, unbiased, and user-friendly readout of amplification reactions outside the model laboratory environment. Dr. Diagnose is an Arduino microcontroller-based light meter that can operate with a portable power bank. It allows the user to select to analyze either fluorescence or turbidity levels in amplification reactions by simply touching the button and informs the user of whether the reaction’s fluorescence or turbidity exceeds a set threshold and is thus considered positive within seconds. The sensitivity of Dr. Diagnose was found to be comparable to gel electrophoresis-based detection. Dr. Diagnose has a simple circuit containing only 13 electronic components, which means it can be easy to generate, affordable, and accessible to the broader community. The development of Dr. Diagnose provides a practical and inexpensive readout tool for amplifications at point-of-need in a rapid, accurate, and user-friendly manner. IMPORTANCE The first critical step in timely disease management is rapid disease identification, which is ideally on-site detection. Of all the technologies available for disease identification, nucleic acid amplification-based diagnostics are often used due to their specificity, sensitivity, adaptability, and speed. However, the modules to interpret amplification results rapidly, reliably, and easily in resource-limited settings at point-of-need (PON) are in high demand. Therefore, we developed a portable, low-cost, and easy-to-perform device that can be used for amplification readout at PON to enable rapid yet reliable disease identification by users with minimal training.