The Biophysical Mechanisms Of Bacterial And Cellular Invasion

Advances in genetics and fluorescent protein chemistry have enabled us to fuse fluorescent probes directly to biomolecules in stably growing organisms; making it easier to image the precise position and movement of cells in three dimensions. Fluorescent stains and dyes can be employed in a similar fashion to visualize nano-scale fluctuations in active cellular structures without fixation. While informative and exciting on a qualitatively level, microscopy truly becomes powerful when we can extract meaningful quantitative information. To accomplish this, custom MATLAB (Mathworks, Natick, MA) image analysis algorithms were developed to specifically measure the biophysical parameters related to pathogenesis and function in microbes and mammalian cells. These parameters can then be exploited in the development of biophysical models to validate current measurements, and make critical predictions about the system's behavior, often addressing quantities inaccessible by experimental methods. The following research chapters of this dissertation thoroughly describe how these techniques were developed and applied to study the biophysical mechanisms of bacterial and cellular invasion.