Date of Award
Master of Science (MS)
Physics and Astronomy
Dr. Gary Hastings
Dr. Brian Thoms
Dr. Eric Gilbert
Dr. Megan Connors
Dr. Nikalous Dietz
Fourier Transform Infrared Spectroscopy (FTIR) is a tool that allows for the characterization of molecular changes in biological systems. In this thesis, FTIR Microscopy is used to investigate the innate response of cells, via their biomolecular compositions, to nutrient stress and drug-induced changes. FTIR was used to study cyanobacteria (Synechocystis sp. PCC 6803 and Spirulina platensis) and algal (Neochloris minuta and Neochloris alveolaris) cells. A strain of yeast (Yarrowia lipolytica), and prostate cancer cells from the PC3 cell line were also studied. The chemometric analysis, in particular, principal component analysis (PCA), was used to differentiate different cell types, cells at various stages of growth, and metabolic modifications in cells in response to external stress.
Changes in the cell biomolecular composition indicate biomarkers that indicate how cells respond to changes in their environment. The cell is in effect a sentinel or biological sensor, which can provide information on drug efficacy, and even on pollutants and other metabolites in the environment in which cells grow, not to mention a variety of pathogenic diseased states of cells.
FTIR spectra of cells provide information on the composition of lipids, carbohydrates, and proteins within the cell. These biomolecules absorb IR radiation for the most part in distinct spectral regions. C-H, N-H, and O-H stretching vibrations occur in the 3300-2800 cm-1 region. Proteins absorb around 1650 and 1550 cm-1. While lipids, including phospholipids, nucleic acids, and polysaccharides display absorption in the 1400-900 cm-1 region.
To test and verify the level of applicability of the FTIR technique we introduce the hypothesis that cyanobacterial cells in various stages of growth can be distinguished based on their FTIR spectrum. Different cyanobacterial strains at similar growth stages can also be characterized. IR spectra of prostate cancer cells in the presence of various drugs were also described based on their FTIR spectra.
Thomas, Jodian Marie, "Fourier Transform Infrared Microscopy for Probing Changes in Biomolecular Composition of Prokaryotic and Eukaryotic Cells in Response to External Stressors." Thesis, Georgia State University, 2018.