(402b) Microfluidic Chip for Patient Sample Isolation Through Immiscible Phases

RNA isolation from a patient sample had been a laborious and time consuming process based on several extractions and centrifugation steps in which they were often limited by small yields and low purities of the separation products. This research project discusses the design of a PDMS microfluidic chip for nucleic acid isolation through two immiscible phases.  The chip allows for a smaller sample size to be used, and for the isolation to occur rapidly by using a filtering barrier to eliminate washing steps, making the microfluidic chip a viable option for use in point-of-care diagnostics. 

The isolation involves: (i) binding the RNA in the patient sample to magnetic beads in the presence of a lysis/binding buffer, (ii) transferring beads through immiscible hydrophobic liquid as a barrier to remove contaminants and purify the RNA, and (iii) the subsequent release of the RNA from the magnetic beads.  As a proof-of-concept, the chip isolation efficiency was evaluated by transferring synthetic single stranded DNA through different width of channels. Microfluidic design was shown to be effective in transporting the nuclei acid bound to the magnetic beads through the chip. The influenza patient samples provided by Rhode Island Memorial Hospital will be further used for isolation and the results will be compared to commercial isolation kits.