3D-printable electrophoretic DNA extraction microdevice for on-site bacterial DNA recovery

Molecular diagnosis is a gold standard method for identifying an infectious disease. DNA extraction from a target pathogen is one of the most important procedures for accurate analysis of the disease-causative pathogen. In this study, a novel 3D-printed electrophoretic DNA extraction microdevice (3D-EDEM) was developed using a digital light processing-stereolithography (DLP-SL) for point-of-care analysis. The 3D-EDEM consists of a source chamber for a bacteria lysate reservoir, a sink chamber for an elution solution container, a hydrogel channel embracing capillary channels that act as a sieving matrix for size-based separation, and two electrode holders for supplying electrical current. Prior to fabricating the 3D-EDEM, UV-curable resin was prepared by using a poly(ethylene glycol) diacrylate (PEG-DA), Irgarcure 819 (IRG), and 2-isopropyl thioxanthone (ITX) as a monomer, a photoinitiator, and a photosensitizer, respectively. The 3D-printed 3D-EDEM provides numerous merits of being inexpensive, reproducible, and convenient, making it more suitable for on-site DNA extraction microdevices than soft-lithographic procedures. For DNA extraction on the 3D-EDEM, Escherichia coli O157:H7 (E. coli) lysate and elution buffer were loaded into the source chamber and the sink chamber, respectively. The optimum DNA extraction time and limit of the DNA extraction test of 3D-EDEM were carried out to evaluate DNA extraction performance, especially using a portable battery. Additionally, the successful DNA extraction test from artificially infected food samples confirms the applicability of the 3D-EDEM to real fields. The proposed 3D-EDEM is adequate for on-site DNA extraction in the field of clinical diagnosis, food safety, environmental monitoring, and forensic analysis.