Ashkan Ojaghi
Date: 12/9/2021
Time: 9am-11am
Location / Meeting Link: IBB Room 1128 / https://bluejeans.com/729174634/7019
Advisor:
Francisco E. Robles, PhD
Committee Members:
Wilbur A. Lam, MD PhD
David R. Myers, PhD
Marcus Cicerone, PhD
Shu Jia, PhD
Deep-Ultraviolet Microscopy and Spectroscopy of Biological Samples
Ultraviolet (UV) spectroscopy is a powerful and well-established tool for quantitative chemical and molecular analysis, however its application to biomedical molecular imaging and microscopy has been limited. Nevertheless, the use of deep-ultraviolet light (i.e., 220-400 nm) offers many potential advantages over traditional microscopy methods, including higher spatial resolution due to the light’s shorter wavelength; and, when combined with spectroscopy, quantitative information with access to many endogenous biomolecules that play an important role in cell and tissue function and structure. This work starts with a brief high-level overview of previous works on label-free optical microscopy techniques to study biological samples. Then, a demonstration of the unique capabilities of deep-UV microscopy is provided, including a hyperspectral interferometric microscopy technique for molecular characterization of live cells. This is followed by a comprehensive study of the optical attenuation and dispersion spectra for several physiologically important biomolecules by which a database for their optical properties in the deep-UV region is established.
By leveraging the biochemical specificity of UV spectroscopy for molecular imaging, a novel label-free assay based on multi-spectral deep-UV microscopy was developed which enabled quantitative assessment of biological samples. We explored the application of this novel assay in hematology analysis as well as cellular phenotyping through imaging of blood and bone marrow samples. Overall, the results of this work can pave the way for label-free optical diagnostic systems for use in clinical and point-of-care settings as well as resource-limited environments.