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

Abstract

Amplification-baseddiagnostics has been widely used in plant disease diagnostics due to its sensitivity, rapidness, and flexibility.The modules to interpret amplificationresults rapidly, reliably, and easily in resource-limited settings (e.g., field-basedenvironments) 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 amplificationreactions 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 fluorescenceor turbidity levels in amplificationreactions by simply touching the button and informs the user of whether the reaction's fluorescenceor 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 amplificationsat point-of-need in a rapid, accurate, and user-friendly manner.