AN INTEGRATED DEVICE FOR SAMPLE PREPARATION, RNA AMPLIFICATION, AND DISEASE DIAGNOSTICS

RNA-based viruses and bacteria have been sources of large-scale epidemics and pandemics, most notably Ebola, SARS, influenza, hepatitis C, HIV, and the Zika Virus. Normal detection of these biological agents requires multiple lab processes, and manual handling and specialized training to perform processes - including sample cell lysing and nucleic acid (RNA/DNA) transportation, and analyzing results. These steps are tedious, expensive, and susceptible to sample contamination. In this project, an inexpensive method was developed to integrate and automate the whole RNA-based infectious disease detection process from sample to answer in a single small Lab-on-a-Chip microfluidic device.

This device incorporates three new engineering techniques: 1) acoustic microstreaming-based micromixers to enhance mixing of biological samples for magnetic RNA binding captures; 2) electrolysis-based micropumps to control fluidic movement; 3) wax valves to manipulate fluid distribution and facilitate RNA separation for amplification, fluorescent-tagging, and analysis. A mathematical theory was developed to optimize acoustic micromixing and acoustic enhancement techniques reduced mixing time from 6 hours to 8 seconds, the electrolysis-based micropumping (NaCl-based) to produce pure hydrogen gas to push liquid on the chip was successfully demonstrated and characterized, and both normally open and normally closed wax microvalves for fluidic manipulation were also successfully demonstrated. The integrated, self-contained device took raw samples from a clinical specimen (urine) with no preparation and automatically performed sample-to-answer genetic analysis for sexual transmitted disease (Chlamydia Trachomatis) detection: yielding high potential in diagnosis of thousands of other RNA-based viral and bacterial diseases.