3D Printed Real-Time PCR Machine for Infectious Disease Diagnostics

Abstract

Diagnosing infectious diseases is a complex task with many different techniques to obtain the results. According to the World Health Organization some diseases such as Malaria and HIV, Polymerase Chain Reaction (PCR) must be used to obtain results and to determine the proper treatment. Ideally, PCR would be used as often as possible because it gives increased reliability and accuracy, but the cost and the difficulty to obtain equipment used for PCR diagnostics outside of a lab environment effectively forces the use of an inferior method of a more accessible nature or treatment without proper diagnosis. The main goal of this research is to develop a system to perform PCR diagnostics that can be manufactured using simple tools, off-the-shelf parts, and a 3D printer. Using a 3D printer allowed for the manufacture of complex parts that would otherwise have to be machined or injection molded, both processes that are out of reach for many. In keeping with this theme, the printed circuit boards were also routed and drilled using the milling tool head of the 3D printer. This was to avoid the complexity of a photochemical process or the poor reliability of a heat transfer method. Few challenges, including difficulty decreasing cycle times, which required designing a heating block that satisfied light-path and thermal requirements, and reading of real-time fluorescence data, were addressed. The resulting device is battery-operated and can perform a complete 40-cycle PCR with real-time fluorescence reading of intercalating dyes. Ultimately, the files for the 3D printed parts can be published and printed out on any 3D printer. This will enable the construction and use of this device in all corners of the globe and without the need for a complex manufacturing process and only standard tools.