Microzone Melting Method of Porous Reactor Fabrication with Structure-Controlled Microchannel Networks for High Yield In Situ DNA Synthesis

This paper presents a simple and cost-effective method for fabricating porous polydimethylsiloxane (PDMS) reactor array chip that is applied in de novo DNA synthesis. A microzone melting technique is proposed in the preparation of a porous PDMS reactor using the sugar particle as a sacrificial template. The curing temperature of 155 °C, higher than the melting point of the sugar particle, is chosen to enhance interconnectivity and reduce internal surface roughness of micropores inside the porous PDMS. The morphological observation and flow resistance test were performed on porous PDMS fabricated with various sugar particle sizes and weight ratios of PDMS to the sugar particle. The results indicate that region I (interconnected pore area) plays a pivotal role in the flow resistance of the porous PDMS reactor. The effectiveness of the porous PDMS reactor in DNA synthesis is verified by gel electrophoresis and fluorescence hybridization. Synthesis product analysis demonstrates that the yield of the porous PDMS reactor is in the same order of magnitude as that of a commercially available 200 nmol synthesis column. The proposed porous PDMS microreactor array chip exhibits great potential in the high-yield DNA synthesis.