A field-deployable mobile molecular diagnostic system for malaria at the point of need

Abstract

In response to the urgent need of a field-deployable and highly sensitive malaria diagnosis, we developed a standalone, “sample-in-answer-out” molecular diagnostic system (AnyMDx) to enable quantitative molecular analysis of blood-born malaria in low resource areas. The system consists of a durable battery-powered analyzer and a disposable microfluidic compact disc loaded with reagents ready for use. A low power thermal module and a novel fluorescence-sensing module are integrated into the analyzer for real-time monitoring of loop-mediated isothermal nucleic acid amplification (LAMP) of target parasite DNA. With 10 μL of raw blood sample, the AnyMDx system automates the nucleic acid sample preparation and subsequent LAMP and real-time detection. Under the laboratory conditions with whole-blood samples spiked with cultured Plasmodium falciparum, we achieved a detection limit of ∼0.6 parasites/μL, much lower than those for the conventional microscopy and rapid diagnostic tests (∼50-100 parasites/μL). The turnaround time from sample to answer is less than 40 minutes. The AnyMDx is user-friendly requiring minimal technological training. The analyzer and the disposable reagent compact discs are cost-effective, making AnyMDx a potential tool for malaria molecular diagnosis under field settings for malaria elimination.

A review of smartphone point‐of‐care adapter design

“…Biological objects such as bacteria, viruses, and parasites are in the micrometer to submicrometer range; therefore, magnification is mandatory for visual inspection of these objects. Smartphone adapters are employed here for visual inspection, measurement, recognition, sensing, and disease diagnosis for conditions such as diabetes, cancer, and malaria . On the other hand, chemical agents, such as hormones, biomarkers, and reagents, are essential for biochemical processes; therefore, smartphone adapters were neatly designed for sensing, measuring, and monitoring these agents, as shown in Figure .…”

“…Smartphone adapters are employed here for visual inspection, measurement, recognition, 126 sensing, 127 and disease diagnosis [128][129][130] for conditions such as diabetes, cancer, 131 and malaria. 132,133 On the other hand, chemical agents, such as hormones, [134][135][136] biomarkers, 137,138 and reagents, 139 are essential for biochemical processes; therefore, smartphone adapters were neatly designed for sensing, measuring, and monitoring these agents, as shown in Figure 5. As depicted in Figure 5A, Skandarajah et al 140 developed a smartphone-based microscope system that is able to perform submicron imaging and compared the performance of the smartphone with that of scientific camera, resulting in comparable images when the smartphone camera resolution was more than 5 megapixels.…”

Sample-to-answer palm-sized nucleic acid testing device towards low-cost malaria mass screening

“…For pan-Plasmodium detection, we adopted a primer set targeting mitochondrial gene common to all Plasmodium species (Polley et al, 2010). For Pf- specific detection, a primer set to specifically detect the mitochondrial gene of Pf was used (Choi et al, 2016; Polley et al, 2010). For Pv- specific detection, we used a primer set targeting cox1 gene of Pv (Britton et al, 2016a).…”

Microfluidic and Paper-Based Devices for Disease Detection and Diagnostic Research

“…One challenge associated with detecting bacteria in the blood is the need to filter out blood cells to identify bacteria, which occur in much lower numbers [ 66 ]. Conversely, the entire sample can be lysed which requires additional analysis steps to enhance the detection of bacterial DNA [ 65 , 67 ]. The filtration or lysis steps can occur directly within the device [ 66 ] or prior to sample analysis [ 65 , 67 ].…”