An automatic integrated microfluidic device for DNA extraction using electric valves

Abstract Deoxyribonucleic Acid (DNA) is a molecule containing genetic instructions that influences the development and function of living organisms. Understanding DNA and its properties is essential for various analytical techniques, such as DNA sequencing, and genetic testing. DNA extraction is a fundamental process that allows scientists to access the genetic information in DNA. There are various methods for DNA extraction from a biological sample which cell lysis and DNA purification are two common steps of them. The chemical cell lysis is selected for this study and a passive micromixer has the microreactor role to mix the lysis buffer and input sample. Also, a silica-based filter is selected for DNA purification. Different units of DNA extraction method are integrated into the fabricated device which includes mixing, lysis and DNA extraction microfluidic chips which are assembled on a chip and form a lab-on-a-chip system that are connected together using electric valves (To open/close system valves to change the flow of different fluids). To optimize the device different parameters including fluid velocity, filter thickness, temperature and cell concentration were studied and the DNA concentration for the optimum values was introduced for 2.5 million cells per milliliter at 65˚C with one silica filter and a vacuum chamber with 25 milliliters. The highest yield for extracted DNA was reported at 147±36 ng/μl, which had a ~90% extraction efficiency in comparison with the reference DNA extraction kit. Finally, the quality of seven samples of extracted DNA from the device was studied using PCR and Gel electrophoresis tests.