Design Of Micro Fluidic Reactor Used In Light-Directed In Situ Synthesis System Of Peptide Nucleic Acids Chips

PNA (Peptide nucleic acid),as analogs of DNA demonstrates a higher specificity and stability in the hybridization reaction with the corresponding DNA/RNA sequences. Thus, PNA chips synthesized by PNA monomers have a wide range of applications in genetic research works as a new type of gene chips in recent years. Among those methods used in the synthesis of PNA chips, the light-directed in situ synthesis technology has shown a brand new competitiveness for its advantages of high-speed and high-density synthesis with lower cost. Micro fluidic reactor as the place that the synthesis takes, its performance directly affects the results of the synthesis.This article designed a new type of micro fluidic reactor innovated in terms of the reactor structure and the shape of the reaction cell, with the desired properties of the flow uniformity, nonrestrictive directivity, air tightness, chemical stability, simplicity and so on. The reactor with the compression-type structure is mainly composed by the base, the reaction cell plate, slide, rubber ring and screwing cap. A variety of positioning and fixing design in the reactor makes it simply to assemble and easy to use. A spindle-shaped reaction cell designed based on bionics is located in the reaction cell plate that was made of PDMS. In order to theoretically prove that the spindle-shaped reaction cell have a better performance in the uniformity of the flow field than the conventional diamond-shaped reaction cell, three group of models with different opening angles (125degrees,135degrees and145degrees) were established to perform simulation using computational fluid dynamics software of Fluent. Analysis of simulation data has shown that the spindle-shaped reaction cell have a higher uniform rate R of velocity, which indicates a better uniformity than the conventional one does. Then, the spindle-shaped reaction cell was optimized based on a further modeling and simulation with increased opening angle and different inlet/outlet width of the reaction cell.The designed reactor was fabricated and assembled to perform a manual experiment and was finally used in the light exposure experiment in the light-directed in situ synthesis system. Ultimately, a PNA pattern that is consistent with the virtual mask pattern was achieved, and verified the effectiveness of the design. This reactor could be widely used in various synthesis systems of gene chips.