Grant: Discovery Grants Program - Individual

Measuring the dielectric properties of cells has important applications in research, biomedical and industrial sectors. For example, in all its manufacturing the biopharma company Biogen maximizes drug productivity using bulk dielectric analysis to control feeding of mammalian cell cultures. Bulk dielectric analysis has limitations due to the inhomogeneous dielectric nature of cells and cell populations. Single cell dielectric analysis is far superior for determining the true dielectric properties of cells in suspension. My program will focus on: 1) Development of an optical transit dielectrophoresis (DEP) cytometer with a highly beneficial combination of throughput, accuracy, analysis time and frequency range. The optical transit DEP cytometer analyzes signals from transit light curves from cells, similar to planets passing in front of a star, to measure particle velocity and infer dielectric properties. Accuracy will be improved using differential signals approaches. Electrodes will be designed to allow analysis frequencies up to 500 MHz, to glean information on cell nuclei and organelles. The channel and detector geometry will be designed to dramatically increase throughput and reduce analysis time. Throughputs of greater than 1000 cells per and the ability to capture mutli-frequency spectra in 10's of seconds. 2) Development of unique dielectric dyes of cellular physiological status. A dielectric dye is a compound that produces a measurable dielectric contrast compared to untreated cells that is dependent on a particular cell property (e.g. biochemical process). For example, exposing a cell to Oligamycin inhibits mitochondrial ATP production. Lower ATP slows membrane ion pumps and causes a drop in cytoplasm conductivity that can be used to estimate the level of mitochondrial ATP production. I propose to test some of the most promising candidates using temporal fits to double shell dielectric models. This unique research will result in new modalities of single cell dielectric analysis. This research will provide a new single cell dielectric analysis tool with a combination of properties, including simple components, that make it a very promising candidate to become one of the preferred methods for single cell dielectric analysis. The dielectric dyes have the potential to expand the types of assays that can be carried out using single cell dielectric analysis. For example, having a simple assay for mitochondrial ATP would have application in biopharma control and for cancer detection where the lack of mitochondrial ATP is considered a hallmark of cancer. The optical transit cytometer single cell dielectric analysis will benefit the Canadian biopharma industries such as Emergent, Therapure, Sanofi by maximizing the productivity of the mammalian cell cultures. With the HQP and technology from this program microfluidics instrumentation companies such as Micralyne and Dalsa will be able to offer new products and markets.