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A Novel Digital Holographic Microscope (DHM) to Investigate and Characterize Microbial Motility in Extreme Aquatic Environments

Citation

Bedrossian, Manuel M. (2020) A Novel Digital Holographic Microscope (DHM) to Investigate and Characterize Microbial Motility in Extreme Aquatic Environments. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/m3a3-4610. https://resolver.caltech.edu/CaltechTHESIS:04272020-152058259

Abstract

Recent shifts in the astrobiological community have prompted the development of methods for the direct search for extant life within our solar system. In order to look for life elsewhere in our solar system, it is important to also investigate the broad spectrum of extant life on Earth. Over millions of years of evolution, life has continually adapted such that an 'extreme' environment has become a relative term. What is considered extreme for one type of organism is home to another and vice versa. Furthermore, very little is known about the organisms that inhabit these extreme environments, and even less in known about their in situ behavior. Investigating various extreme environments around Earth in order to understand the in situ behavior of organisms that inhabit it will better inform the astrobiological community when planning future space missions for the direct search for extant life within our solar system. However, no suitable instrument exists to conduct these in situ field campaigns, while also being physically robust enough to withstand the rugged terrains that can be expected from extreme environments.

This thesis describes the development of a novel off-axis digital holographic microscope (DHM) for the direct in situ observation of microscale organisms in extreme aquatic environments. The hardware developments of this instrument are introduced and validated experimentally as well as software developments including autonomous particle detection and tracking algorithms. This instrument is then used in novel laboratory experiments involving the development of optical phase contrast agents, as well as deployed to multiple field campaigns where off-axis DHM is used to observe the in situ behavior of microorgansisms in various extreme aquatic environments around North America.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Digital Holographic Microscopy; microscopy; life detection; extreme environments; microbiology; astrobiology; medical engineering; optical imaging, volumetric imaging
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Medical Engineering
Awards:Demetriades-Tsafka-Kokkalis Prize in Biotechnology or Related Fields, 2020.
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Gharib, Morteza
Thesis Committee:
  • Shapiro, Mikhail G. (chair)
  • Ismagilov, Rustem F.
  • Nadeau, Jay L.
  • Gharib, Morteza
Defense Date:20 April 2020
Record Number:CaltechTHESIS:04272020-152058259
Persistent URL:https://resolver.caltech.edu/CaltechTHESIS:04272020-152058259
DOI:10.7907/m3a3-4610
Related URLs:
URLURL TypeDescription
https://doi.org/10.1080/23746149.2018.1424032DOIArticle adapted for a section of Chapter 1.
https://doi.org/10.1371/journal.pone.0147700DOIArticle adapted for a section of Chapter 3.
https://doi.org/10.1089/ast.2016.1616DOIArticle adapted for a section of Chapter 4.
https://doi.org/10.3791/56343DOIArticle adapted for a section of Chapter 4.
https://doi.org/10.1117/12.2250069DOIArticle adapted for a section of Chapter 4.
https://doi.org/10.3934/biophy.2018.1.36DOIArticle adapted for a section of Chapter 5.
ORCID:
AuthorORCID
Bedrossian, Manuel M.0000-0003-2524-3765
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:13684
Collection:CaltechTHESIS
Deposited By: Manuel Bedrossian
Deposited On:12 May 2020 16:04
Last Modified:15 Dec 2020 16:45

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