Adesemoye, Modupe Chetachi Shalom (2019-12). Toward Point-of care Detection of Tuberculosis Using a Magnetic Cell Separation Microfluidic Platform. Master's Thesis.
Thesis
Tuberculosis (TB) is a deadly disease that has claimed the lives of many across the world. According to the data from the Center for Diseases Control and Prevention (CDC), one-fourth of the world's population was infected with TB. In 2017, 10 million people in the world became sick with TB, and there were 1.3 million TB-related deaths world-wide. The need for early and fast detection of TB cells in potentially infected individuals is a critical first step to saving lives. This work presents a microfluidic platform for the detection of tuberculosis using magnetic nanobeads with bound phage tail fiber protein that specifically recognizes mycobacterial cells. This cell isolation is performed through a lateral magnetophoretic microfluidic device, where a magnetic bar placed at the bottom of the substrate of a microchannel allows the capture of mycobacterial cells flowing through the microchannel. The capability of the developed microfluidic device in its ability to isolate mycobacterial cells was tested. Here, Mycobacterium smegmatis, a safe biosafety level 1 model organism, was utilized instead of Mycobacterium tuberculosis, the TB-causing pathogen, since M. smegmatis resembles many features of M. tuberculosis and can be utilized safely. Separation of M. smegmatis from a buffer solution achieved a maximum separation efficiency of 34% at a flow rate of 200ul. Compared to conventional magnetic separation assay, the use of a microfluidic device eliminates the multi-step assay step, including centrifugation, and leads to reduced time, sample and reagent consumption, as well as more complex equipment and operation need. Lastly, mycobacterium separation test was conducted in the presence of other bacteria cells to see the occurrence of false positives in the presence of such cells. When E. coli was mixed with M. smegmatis at a ratio of 1:6, 1:60, and 1:6000, the separation efficiency did drop a little bit, but it was still possible for the device to have at least 7% separation efficiency. The experimental results show that M. smegmatis can be successfully isolated using the developed magnetophoretic microfluidic platform, showing the potential of a more cost-effective and point-of-care method for TB detection.
