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Retrospective Theses and Dissertations

Physical Sciences and Mathematics

Analytical chemistry

Articles 1 - 10 of 10

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Subunits Of Highly Fluorescent Protein R-Phycoerythrin As Probes For Cell Imaging And Single-Molecule Detection , Dragan Isailovic Jan 2005

Subunits Of Highly Fluorescent Protein R-Phycoerythrin As Probes For Cell Imaging And Single-Molecule Detection , Dragan Isailovic

Retrospective Theses and Dissertations

R-phycoerythrin (R-PE) subunits and enzymatic digests were characterized by high-performance liquid chromatography (HPLC), capillary and gel electrophoresis, and HPLC-electrospray ionization mass spectrometry. Subunits were isolated from R-PE by HPLC and detected as single molecules by total internal reflection fluorescence microscopy (TIRFM). Favorable spectroscopic characteristics of R-PE subunits and digest peptides in the visible region of spectrum originate from phycoerythrobilin (PEB) and phycourobilin (PUB) chromophores. High absorption coefficients and fluorescence (even under denaturing conditions), broad excitation and emission fluorescence spectra, and low molecular weights make these molecules suitable for fluorescence labeling of biomolecules and cells.;Fluorescent proteins were further formed both ...


Real-Time Monitoring And Manipulation Of Single Bio-Molecules In Free Solution , Hung-Wing Li Jan 2005

Real-Time Monitoring And Manipulation Of Single Bio-Molecules In Free Solution , Hung-Wing Li

Retrospective Theses and Dissertations

The observation and manipulation of single biomolecules allow their dynamic behaviors to be studied to provide insight into molecular genetics, biochip assembly, biosensor design, DNA biophysics.;In a PDMS/glass microchannel, a nonuniform electroosmotic flow (EOF) was created. By using a scanning confocal fluorescence microscope and total internal-reflection fluorescence microscope (TIRFM), we demonstrated that negatively charged DNA molecules were focused by the nonuniform EOF into a thin layer at the glass surface. This phenomenon was applied to selectively detect target DNA molecules without requiring the separation of excessive probes and can be applied continuously to achieve high throughput.;A variable-angle-TIRFM ...


Nonphotochemical Hole-Burning Imaging Studies Of In Vitro Carcinoma And Normal Cells Utilizing A Mitochondrial Specific Dye , Richard Joseph Walsh Jan 2002

Nonphotochemical Hole-Burning Imaging Studies Of In Vitro Carcinoma And Normal Cells Utilizing A Mitochondrial Specific Dye , Richard Joseph Walsh

Retrospective Theses and Dissertations

Low temperature Nonphotochemical Hole Burning (NPHB) Spectroscopy of the dye rhodamine 800 (MF680) was applied for the purpose of discerning differences between cultured normal and carcinoma ovarian surface epithelial (OSE) cells. Both the cell lines were developed and characterized at the Mayo Clinic (Rochester, MN), with the normal cell line having been transfected with a strain of temperature sensitive Simian Virus 40 Large T Antigen (SV40) for the purpose of extending the life of the cell culture without inducing permanent changes in the characteristics of the cell line. The cationic lipophilic fluorophore rhodamine 800 preferentially locates in in situ mitochondria ...


Analytical Chemistry At The Interface Between Materials Science And Biology , Janese Christine O'Brien Jan 2000

Analytical Chemistry At The Interface Between Materials Science And Biology , Janese Christine O'Brien

Retrospective Theses and Dissertations

This work describes several research efforts that lie at the new interfaces between analytical chemistry and other disciplines, namely materials science and biology. In the materials science realm, the search for new materials that may have useful or unique chromatographic properties motivated the synthesis and characterization of electrically conductive sol-gels. In the biology realm, the search for new surface fabrication schemes that would permit or even improve the detection of specific biological reactions motivated the design of miniaturized biological arrays. Collectively, this work represents some of analytical chemistry's newest forays into these disciplines;This dissertation is divided into six ...


Inductively Coupled Plasma Mass Spectrometry For Stable Isotope Metabolic Tracer Studies Of Living Systems , Elise Tuy Luong Jan 1999

Inductively Coupled Plasma Mass Spectrometry For Stable Isotope Metabolic Tracer Studies Of Living Systems , Elise Tuy Luong

Retrospective Theses and Dissertations

Sub-nanogram per gram levels of molybdenum (Mo) from human blood plasma are isolated by the use of anion exchange alumina microcolumns. Million-fold more concentrated spectral and matrix interferences such as sodium, chloride, sulfate, phosphate, etc. in the blood constituents are removed from the analyte. The recovery of Mo from the alumina column is 82 +/- 5% (n = 5). Isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS) is utilized for the quantitative ultra-trace concentration determination of Mo in bovine and human blood samples. The average Mo concentration in reference bovine serum determined by our method is 10.2 +/- 0.4 ng/g ...


An Integrated Multiple Capillary Array Electrophoresis System For High-Throughput Dna Sequencing , Xiandan Lu Jan 1998

An Integrated Multiple Capillary Array Electrophoresis System For High-Throughput Dna Sequencing , Xiandan Lu

Retrospective Theses and Dissertations

Capillary array electrophoresis system was chosen to perform DNA sequencing because of several advantages such as rapid heat dissipation, multiplexing capabilities, gel matrix filling simplicity, and the mature nature of the associated manufacturing technologies;There are two major concerns for the multiple capillary systems. One concern is inter-capillary cross-talk and the other concern is excitation and detection efficiency. Cross-talk is eliminated through proper optical coupling, good focusing and immersing capillary array into index matching fluid. A side-entry excitation scheme with orthogonal detection was established for large capillary array. Two 100 capillary array formats were used for DNA sequencing. One format ...


On-Line Coupling Of Capillary Electrophoresis And Liquid Chromatography With Electrospray Ionization Mass Spectrometry For Protein Characterization , Liyu Yang Jan 1998

On-Line Coupling Of Capillary Electrophoresis And Liquid Chromatography With Electrospray Ionization Mass Spectrometry For Protein Characterization , Liyu Yang

Retrospective Theses and Dissertations

On-line coupling of capillary isoelectric focusing (CIEF) and liquid chromatography (LC) with electrospray ionization mass spectrometry (ESIMS) is utilized for protein characterization;A microdialysis junction, based on a microdialysis membrane connecting both a separation capillary and a short, sharply tapered microelectrospray emitter capillary, is demonstrated for CIEF-ESIMS. Besides the electrical connection across the microdialysis junction, post-run acidification via the dialysis membrane is demonstrated for enhancing the protonation and the ionization efficiency of focused proteins while maintaining separation efficiency, resolution, and sensitivity in CIEF-ESIMS;On-line combination of CIEF with ESI-FTICRMS is demonstrated for high resolution analysis of model proteins, human hemoglobin ...


Monitoring Protein Refolding Using Diverse Separation And Spectroscopy Techniques , Pamela Kay Jensen Jan 1997

Monitoring Protein Refolding Using Diverse Separation And Spectroscopy Techniques , Pamela Kay Jensen

Retrospective Theses and Dissertations

Rapid growth in the biotechnology industry has led to a dramatic increase in attention to the protein folding problem. Understanding of protein folding is essential to the production of biopharmaceuticals since commercial production of recombinant proteins often requires a protein refolding process to recover high yields;Capillary zone electrophoresis (CZE) equipped with laser induced fluorescence detection (LIFD) is developed as a tool for monitoring the refolding of a model protein, phage P22 tailspike endorhamnosidase. Intermediates on the folding pathway are separated in CZE and monitored by their intrinsic tryptophan fluorescence. Monitoring refolding of tailspike by traditional methods, sodium dodecyl sulfate-polyacrylamide ...


Improved Resins And Novel Materials And Methods For Solid Phase Extraction And High Performance Liquid Chromatography , Ronald Carl Freeze Jan 1997

Improved Resins And Novel Materials And Methods For Solid Phase Extraction And High Performance Liquid Chromatography , Ronald Carl Freeze

Retrospective Theses and Dissertations

Solid-phase extraction (SPE) has grown to be one of the most widely used methods for isolation and preconcentration of a vast range of compounds from aqueous solutions. By modifying polymeric SPE resins with chelating functional groups, the selective uptake of metals was accomplished. By reducing the size of the resin beads and optimizing reaction conditions, resins were produced which had excellent capacities both in the packed-column and the suspension mode. By reducing bead sizes to 1 [mu]m, direct injection of the beads into an inductively coupled plasma (ICP) torch was possible. The resin, along with adsorbed metals, was vaporized ...


Applications Of Partial Filling Micellar Electrokinetic Chromatography: From Electrospray Mass Spectrometry To Fluorescence Polarization Immunodetection , Wendy Marie Nelson Jan 1996

Applications Of Partial Filling Micellar Electrokinetic Chromatography: From Electrospray Mass Spectrometry To Fluorescence Polarization Immunodetection , Wendy Marie Nelson

Retrospective Theses and Dissertations

Mechanistic studies of partial filling micellar electrokinetic chromatography PF-MEKC) and a theoretical model for the prediction of separation behavior in PF-MEKC was developed in this work. Along with the theoretical development of PF-MEKC, two different detection modes were applied to PF-MEKC, in contrast to the traditional UV detection used in micellar electrokinetic chromatography (MEKC). The first detection mode coupled PF-MEKC with eletrospray ionization mass spectrometry. The second detection mode developed in this work is PF-MEKC coupled with fluorescence polarization immunodetection;First, in the mechanistic studies of PF-MEKC a theoretical model was proposed for predicting the separation behavior of triazine herbicides ...