Design and Fabrication of a Centrifugal Microfluidic System to DNA Extraction

Fathi Ganje Lou, Ali | 2020

671 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 52959 (06)
  4. University: Sharif University of Technology
  5. Department: Chemical and Petroleum Engineering
  6. Advisor(s): Farhadi, Fathollah; Saadatmand, Maryam; Parsa Yeganeh, Laleh
  7. Abstract:
  8. Deoxyribonucleic acid (DNA) extraction, as one of the most important steps in modern molecular diagnostics, is the process by which DNA is separated from intracellular materials like proteins, membranes, and other materials contained in the cell. Microfluidic technology enables sophisticated, time-consuming and costly experiments with minimal use of raw materials, time and cost and acceptable accuracy. The predominant advantages of centrifugal microfluidic systems are utilizing centrifugal force to generate propulsion without the need for a pump, and eliminating the need for experts to run the system. Various fluidic operations such as valving, mixing, metering, heating, and sample separation can be performed on these systems. Traditional methods of DNA extraction and purification are based on liquid-liquid extraction or solid-phase extraction technology, which are very laborious and time-consuming, and may lead to sample contamination and laboratory error. In this work, the design and characterization of a completely passive lab-on-a-disk system for DNA purification were presented. The developed configuration employed passive pneumatic and inertial forces for fluidic mixing and pumping of the reagents. Modified septum valves and a siphon valve were used to conduct the fluidic sequence of the reagents. These modified septum valves reduced the leakage of the reagents into the mixing chamber compared to that of ordinary septum valves. Experiments first were conducted using dyed water as representative of actual DNA extraction reagents and a successful rotation protocol of DNA purification from lysate was obtained. Binding, washing and eluting steps were automatically performed on the proposed Lab-disk by dyed water. Then actual DNA extraction reagents were used to perform the automatic and semi-automatic DNA purification on the Lab-disk using the obtained rotation protocol. As a proof of concept, the purified DNA samples were collected and tested with several methods, including DNA gel electrophoresis and PCR and the purity and concentration of the purified DNA samples were obtained using a spectrophotometer. The concentrations of the purified DNA samples collected from the semi-automatic disk and the automatic disk were about 99.1% and 94.9% of that obtained from using the Silica Column DNA extraction method. The simplicity and cost-effectiveness of the design and fabrication of the proposed lab-disk, along with its proper performance, paves the way to achieve a sample to answer molecular diagnostic system by adding additional operating units
  9. Keywords:
  10. Centrifugal Microfluidics ; Pneumatic Forces ; Inertial Forces ; Lab-on-a-CD (LOCD) ; Point of Care Diagnosis Systems ; White Blood Cell ; DNA Extraction

 Digital Object List