Programmable magnetic robot (ProMagBot) for automated nucleic acid extraction at the point of need

Abstract

Upstream sample preparation remains the bottleneck for point-of-need nucleic acid testing due to its complexity and time-consuming nature. Sample preparation involves extracting, purifying, and concentrating nucleic acids from various matrices. These processes are critical for ensuring the accuracy and sensitivity of downstream nucleic acid amplification and detection. However, current sample preparation methods are often laboratory-based, requiring specialized equipment, trained personnel, and several hours of processing time. As a result, sample preparation often limits the speed, portability, and cost-effectiveness of point-of-need nucleic acid testing. A universal, field-deployable sample preparation device is highly desirable for this critical need and unmet challenge. Here we reported a handheld, battery-powered, reconfigurable, and field-deployable nucleic acid sample preparation device. A programmable electromagnetic actuator was developed to drive a magnetic robot (ProMagBot) in X/Y 2D space, such that various magnetic bead-based sample preparations can be readily translated from the laboratory to point-of-need settings. The control of the electromagnetic actuator requires only a 3-phase unipolar voltage in X and Y directions, and therefore, the motion space is highly scalable. We validated the ProMagBot device with a model application by extracting HIV viral RNAs from plasma samples using two widely used magnetic bead kits: ChargeSwitch and MagMAX beads. In both cases, the ProMagBot could successfully extract viral RNAs from 50 μL plasma samples containing as low as 10² copies of viral RNAs in 20 minutes. Our results demonstrated the ability of ProMagBot to prepare samples from complex mediums at the point of need. We believe such a device would enable rapid and robust sample preparation in various settings, including resource-limited or remote environments, and accelerate the development of next-generation point-of-need nucleic acid testing.