Figure 1. Concept of using modified 3D printer to carry out molecular diagnostics.

(a) Rapid and low-cost diagnostics for ZIKV using a modified entry-level 3D printer. The printer was reversibly-converted to automate magnetic particle-based nucleic acid extraction. The 3D printer’s motions are controlled by G-codes and can easily be written to perform extraction protocols. A deep-profile 96-well microplate can be used to hold samples and reagents for processing multiple samples. The templates can be amplified by real-time reverse transcription recombinase polymerase amplification reaction (RT-RPA) using the printer’s heating element (a heated bed or filament extruder). Alternatively, the templates can be amplified by RT-PCR using a low-cost Thermos Thermal Cycler. Results were confirmed by post-PCR fluorescence analysis using a smartphone camera. (b) Converting a low-cost 3D printer to perform rapid and automated nucleic acid isolation and real-time RPA amplification. The extruder was removed to allow the adaptors to be mounted. The magnetic particle processor attachment (MPPA) was attached to the adaptor by a luer-lock mechanism. Its vertical and lateral movements were controlled by the Z-motor and the X and Y platform control. The disposable tip-comb housed a set of magnetic rods controlled by the extruder motor. The tip-comb and magnetic rods perform MP capture and resuspension via the Z-axis motor and extruder motor. There was no direct contact between the magnets, and the samples and MPs. The printer bed holds a 96-well deep-well microplate or pre-loaded cartridges. Depending on the orientation of the plate, 8 or 12 samples can be processed simultaneously.