Dielectrophoretic characterization and separation of leukocytes

Official URL: http://risc01.sabanciuniv.edu/record=b1817057 (Table of Contents)

Characterization and separation of leukocytes are critical for precision in medical diagnostics, treatment and biomedical research. Existing characterization and separation methods are generally based on centrifugation or antibody-mediated recognition assays. Even though these methods are highly sensitive and specific, they are sometimes inefficient and require several preparative steps involving heavy equipment. Moreover, antibody labeling might cause biases during characterization and change the cell phenotype, particularly for immunological cells that can quickly respond and adapt to environmental changes. Dielectrophoresis (DEP) has a great potential for noninvasive manipulation of cells based on their dielectric characteris­tics. It is a favorable alternative to the current cell manipulation methods by being label-free, low-cost, fast and accurate. In this thesis, dielectrophoretic character­ization of U937 monocytes, macrophages, dead cells and monocytes stained with commercially available fluorescent dyes are presented using a 3D carbon-electrode DEP device. Also, a new DEP model is proposed, and dielectrophoretic character­ization of leukocytes and RBCs were performed using the proposed model. Then, live-dead leukocytes and monocytes-macrophages were separated successfully based on differences between their dielectric properties, while preserving their viability. This approach will reduce the dead cell contamination risk in blood analyses and increase the precision in disease diagnostics by achieving more reliable and accurate test results.