Electronic Thesis and Dissertation Repository


Master of Science




Dr. John R. de Bruyn

2nd Supervisor

Dr. Bryan Heit

Joint Supervisor


The diffusion of CD93, a putative efferocytic receptor, was studied in the membrane of human monocytes and CHO cells using single particle tracking. We found that of CD93 molecules were confined in compartments consistent with actin corrals, while moved freely. Cage effect analysis showed short-lived caging of free CD93 and longer-lasting caging of confined CD93, with smaller corrals resulting in stronger caging. The motion of both free and confined CD93 was found to be consistent with a subdiffusive continuous time random walk, suggesting that CD93 diffusion is affected by several processes. We also sought to develop a total internal reflection fluorescence compatible traction force microscopy substrate intended for use in force characterization in frustrated efferocytosis. TIRF-compatible silicone substrates of a uniform thickness were manufactured successfully, but were found to be unsuitable for reliable force measurements due to their susceptibility to the non-specific adsorption of quantum dots.

Mov1.avi (4884 kB)
Movie 1 - Free Ensemble

Mov2.avi (4680 kB)
Movie 2 - 200 nm Confined Ensemble