Single Cell Visualization of DNA Repair Using Digital Fluorescent Holography

Brandeis University, Waltham MA

Investigators

Abstract

In this project, in order to understand the process of the repair of broken chromosomes the PI will visualize their motion in vivo. The physical properties of chromosomes such as the end-to-end distance, collision rate and the cyclization rate will be measured for comparison to the prediction of theoretical models of biopolymers. The affects of the physical constraints such as the chromosomal tethering to the nuclear periphery as well as the variation in homology length will be addressed systematically. A novel fluorescent holographic microscope will be used to improve current methods of three-dimensional microscopy and to visualize the dynamics of these biopolymers. The experiments will be performed in a microfluidic device where a precise control over the microenvironment of cells is possible. Using a microfluidic progeny chamber in combination with precise image analysis, the PI will investigate the repair process at the single cell level and characterize the cell-to-cell variability of the repair process. The PI has modified an existing lecture course for freshman in biophysics to include experiments in modern quantitative biology. The PI has also started a collaborative effort among the Departments of Physics, Biology and the Education Program at Brandeis University to launch a summer workshop for high school teachers in the subject of modern methods of microscopy applied to quantitative biology. The workshop will familiarize high school teachers with cutting edge techniques in quantitative biology and give them ideas for new experiments in their classrooms. The participants will take home all the materials that they had used during the workshop, including the inexpensive student-grade fluorescent microscope that the PI has co-developed at Brandeis University and the pre-made fluorescent slides for use in their schools science program.