The refractive index of phytoplankton has never been directly measured before despite its importance towards studying the optical characteristics of marine particles. Previous attempts to measure it have been done through indirect methods. While these methods have proven useful, they contain assumptions about the particles morphology and composition that cause for uncertainty with the measurements. Through the use of the 3D Cell Explorer, a high precision holotomographic microscope, the RI of phytoplankton can be directly measured for the first time. With volume measurements, the phytoplankton were found to not display a single bulk RI, instead the bulk RI was different for distinct groups, largely differentiated by external membrane (Diatoms, Coccolithophores, Dinoflagellates, and Ciliates). Additionally, differences between species were seen in the volume portions of different structures, further necessitating the use of different bulk RIs for different species of phytoplankton. The bulk RI for diatoms shows strong agreement with previous data, validating this method as a way to directly measure the RI of phytoplankton moving forward.
","abstract_html":"<p>The refractive index of phytoplankton has never been directly measured before despite its importance towards studying the optical characteristics of marine particles. Previous attempts to measure it have been done through indirect methods. While these methods have proven useful, they contain assumptions about the particles morphology and composition that cause for uncertainty with the measurements. Through the use of the 3D Cell Explorer, a high precision holotomographic microscope, the RI of phytoplankton can be directly measured for the first time. With volume measurements, the phytoplankton were found to not display a single bulk RI, instead the bulk RI was different for distinct groups, largely differentiated by external membrane (Diatoms, Coccolithophores, Dinoflagellates, and Ciliates). Additionally, differences between species were seen in the volume portions of different structures, further necessitating the use of different bulk RIs for different species of phytoplankton. The bulk RI for diatoms shows strong agreement with previous data, validating this method as a way to directly measure the RI of phytoplankton moving forward.</p>","abstract_has_math":false,"creators":["Kamowski, Michael"],"institution":null,"degree_name":"Master of Science (MS)","degree_level":"Masters Thesis","degree_discipline":null,"degree_department":null,"school":null,"contributors":["Dr. Xiaodong Zhang","Dr. Kristina Mojica","Dr. Christopher Hayes"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2023,"date_issued":"2023-05-11T07:00:00Z","date_published":"2023-05-11T07:00:00Z","updated_at":"2026-07-24T05:45:40Z","subjects":["Optics","Phytoplankton","Refractive Index","Modeling","Scattering","Oceanography"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://aquila.usm.edu/masters_theses/964","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Dr. Xiaodong Zhang","Dr. Kristina Mojica","Dr. Christopher Hayes"]},{"key":"dc:creator","label":"Author","values":["Kamowski, Michael"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2024-01-23T08:00:00Z"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Masters Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Optics","Phytoplankton","Refractive Index","Modeling","Scattering","Oceanography"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://aquila.usm.edu/masters_theses/964"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The refractive index of phytoplankton has never been directly measured before despite its importance towards studying the optical characteristics of marine particles. Previous attempts to measure it have been done through indirect methods. While these methods have proven useful, they contain assumptions about the particles morphology and composition that cause for uncertainty with the measurements. Through the use of the 3D Cell Explorer, a high precision holotomographic microscope, the RI of phytoplankton can be directly measured for the first time. With volume measurements, the phytoplankton were found to not display a single bulk RI, instead the bulk RI was different for distinct groups, largely differentiated by external membrane (Diatoms, Coccolithophores, Dinoflagellates, and Ciliates). Additionally, differences between species were seen in the volume portions of different structures, further necessitating the use of different bulk RIs for different species of phytoplankton. The bulk RI for diatoms shows strong agreement with previous data, validating this method as a way to directly measure the RI of phytoplankton moving forward.
"]},{"key":"dc:title","label":"Title","values":["Determining the Refractive Index of Phytoplankton via Direct Measurement of Cellular Structures"]}]}],"canonical_facts":{"dc:contributor":["Dr. Xiaodong Zhang","Dr. Kristina Mojica","Dr. Christopher Hayes"],"dc:creator":["Kamowski, Michael"],"dc:date.available":["2024-01-23T08:00:00Z"],"dc:description.abstract":["The refractive index of phytoplankton has never been directly measured before despite its importance towards studying the optical characteristics of marine particles. Previous attempts to measure it have been done through indirect methods. While these methods have proven useful, they contain assumptions about the particles morphology and composition that cause for uncertainty with the measurements. Through the use of the 3D Cell Explorer, a high precision holotomographic microscope, the RI of phytoplankton can be directly measured for the first time. With volume measurements, the phytoplankton were found to not display a single bulk RI, instead the bulk RI was different for distinct groups, largely differentiated by external membrane (Diatoms, Coccolithophores, Dinoflagellates, and Ciliates). Additionally, differences between species were seen in the volume portions of different structures, further necessitating the use of different bulk RIs for different species of phytoplankton. The bulk RI for diatoms shows strong agreement with previous data, validating this method as a way to directly measure the RI of phytoplankton moving forward.
"],"dc:identifier":["https://aquila.usm.edu/masters_theses/964"],"dc:subject":["Optics","Phytoplankton","Refractive Index","Modeling","Scattering","Oceanography"],"dc:title":["Determining the Refractive Index of Phytoplankton via Direct Measurement of Cellular Structures"],"thesis:degree_level":["Masters Thesis"],"thesis:degree_name":["Master of Science (MS)"]},"updated_at":"2026-07-24T05:45:40Z"}