Fabrication of a 3D Teflon microdevice for energy free homogeneous liquid flow inside a long microchannel and its application to continuous-flow PCR

Abstract

We introduce a simple but robust manufacturing technology for a 3D spiral Teflon microdevice, by wrapping a polytetrafluoroethylene (PTFE) tube around a poly(dimethylsiloxane) (PDMS) mold. Semi-automated sample injection inside this fluoroplastic microdevice was achieved using one disposable syringe with flow rates systemically analyzed under different inner pressures and syringe volumes. After placing the microdevice on a single hot plate at a constant temperature of 105 °C, a temperature gradient was formed across the 3D spiral fluoroplastic microdevice, which is suitable for the successful amplification of two DNA targets (230 bp and 409 bp) from a plasmid vector. In contrast with PDMS and poly(methyl methacrylate) (PMMA) microdevices, fewer bubbles were observed in this Teflon microdevice. The effect of the Teflon surface on amplification efficiency was also analyzed. After adding different amounts of bovine serum albumin (BSA) to the same volume of polymerase chain reaction (PCR) solution, it was found that the amplification efficiency increased when BSA concentration was adjusted from 0 to 0.24 μg μL⁻¹. Futhermore, we believe that this 3D spiral fluoroplastic microdevice could be a stable platform for continuous-flow PCRs.