An Enhanced Optical Coherence Microscope for the Study of Dynamic Processes in the Early Development of Plants and Animals

Harvey Mudd College, Claremont CA

Investigators

Abstract

A grant has been awarded to Dr. Richard Haskell at Harvey Mudd College to construct an optical coherence microscope (OCM) to capture three-dimensional images of dynamic processes in the early development of plants and animals. An interdisciplinary team of scientists and engineers at Harvey Mudd will record critical events that occur 300 to 500 mm below the surface of a developing organism, too deep to be accessible to other light-based methods because of the strong light-scattering property of embryonic tissue. The ability of the OCM instrument to image non-invasively the development of an individual plant or animal will provide a key tool for gaining a full understanding of the relationship between gene expression and the structural changes that occur during tissue development. The light source of the OCM instrument will be an ultrafast laser operating in the near infrared (1300 nm) to provide good depth penetration in biological tissue. The laser output will have a broad spectrum that results in a depth resolution for the microscope of 5 mm. The lateral resolution is provided by the focused spot diameter, also 5 mm. The laser system developed for the OCM will be marketed by a commercial vendor so that it is available to other researchers. In addition, the instrument will be capable of measuring scatter motion, for example Brownian motion, which in preliminary experiments has been shown to provide effective intrinsic contrast between different cell types. Measurements of the local variation in refractive index will also serve as a source of intrinsic contrast. The new OCM instrument will be used to study the development of frog embryos and the differentiation of tissue at the apex of plant shoots. OCM images will be assembled to form time-lapse images of dynamic processes, permitting the first direct tests of proposed models of cell motions and differentiation. The research team will consist primarily of four faculty at Harvey Mudd College plus collaborators at four research universities. Their backgrounds span the disciplines of physics, biology, and engineering. An estimated 30 undergraduate researchers, drawn from all 6 major programs at Harvey Mudd, will make significant contributions to the program both during the summer and the academic year. The multidisciplinary nature of the project provides an unusual opportunity to integrate research and education resulting in exceptional training for students and faculty alike. Participants are motivated to develop careers in science and engineering, and to pursue significant research problems that stretch across traditional disciplinary lines.