Multiplex Magnetofluidic Nucleic Acid Amplification Test (NAAT) Platform with Spatially Arrayed Sample Splitting

With development of faster genome sequencing technology in the past few decades, molecular diagnostics have emerged as a valuable tool to detect various infectious diseases. Nucleic acid amplification test (NAAT), utilizing polymerase chain reaction (PCR), could detect even miniscule fragments of genetic material of the target pathogen with high specificity. Its exceptional performance allowed it to become a widely used diagnostic method in many clinical laboratories in the United States. However, NAAT has limited use around the globe, especially in developing countries, due to its high cost and complexity in sample preparation and testing procedures that require trained laboratory personnel. In response to these shortcomings of NAAT, our lab has developed portable and easy-to-use NAAT platforms that feature automated sample preparation with droplet magnetofluidic (DM) technology. With these platforms, healthcare professionals in the local clinics could perform the test with only minimal training. The results could be obtained within an hour, and the patients can receive their diagnosis on the spot without paying extra visits to clinical laboratories. Though these platforms provide rapid point-of-care (POC) testing, they could be further improved with various features such as multiplexing. Multiplexing allows simultaneous detection of multiple targets from one sample, and the technology is especially useful for screening various pathogens and detecting antibiotic resistance of identified pathogens. In this thesis, we aim to innovate a portable, inexpensive, multiplex NAAT platform that utilizes DM technology to spatially split the samples for multiple target detection. In addition, we attempt to lower the cost of the instrument further by using an inexpensive CMOS camera for data acquisition, in place of a confocal fluorescence detector that had been used previously. So far, we have built two independent prototype platforms for the magnetofluidic spatial sample splitting and multiplex thermal cycling. We also fabricated various designs of multiplex cartridges and have tested them on the platforms. The work presented here will serve as a solid basis for the development of the multiplex magnetofluidic NAAT platform with its novel spatially arrayed magnetofluidic sample splitting