Fast DNA Microarray Hybridization On A Pneumatic Micromixing Device

The fast and efficient molecular hybridization has an important effect on modern molecular biology and its clinical application. And the importance has been an increasing attention to academics. In the present work, a pneumatic micromixing device with high efficiency, automation, miniaturization and low cost was manufactured using polydimethylsiloxane (PDMS) and glass slide. Based on this micromixing device, a rapid and efficient DNA hybridization process was accomplished using polyacrylamide gel as DNA immobilization carrier.In Chapter1, the significance, development and popular methods of DNA hybridization were reviewed. Besides, the working principle of DNA solid-phase hybridization using3-D polyacrylamide gel as carrier and the development of DNA hybridization-based microarray platforms were described. At last, the consideration of our work design was given.In Chapter2, a microfluidic mixing chip using PDMS and glass slide as processing materials was presented. The fluid in the chip can be rapidly mixed by pneumatic oscillating actuation. The control parameters of the pneumatic mixing device using the fluid mixing were given:the thickness of PDMS, the nitrogen pressure and actuation frequency In the fluid mixing experiment, a2-μL rhodamine6G solution was efficiently mixed within2s in the19μL chamber with the thickness of driving membrane100μm; the nitrogen pressure0.08MPa, and the actuation frequency24Hz.In Chapter3, a rapid and efficient DNA hybridization system was developed using polyacrylamide gel as DNA immobilization carrier on the pneumatic micromixing chip. The effects of reaction time and the oligonucleotide concentration on DNA hybridization efficiency were investigated. Under the optimized conditions, DNA hybridization was greatly accelerated using this pneumatic mixing device and the fluorescence intensity showed a plateau after30s. Comparing with the traditional hybridization for30s at42℃, the fluorescence signal levels of the dynamic hybridization were11.5-fold higher with sample concentration of40μmol/L and probe concentration of1μmol/L. In the last chapter, a summary and perspective were given for this rapid and highly efficient DNA hybridization system on the pneumatic micromixing chip.