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

Understanding Protein Motions By Computational Modeling And Statistical Approaches, Lei Yang Jan 2008

Understanding Protein Motions By Computational Modeling And Statistical Approaches, Lei Yang

Retrospective Theses and Dissertations

Because of its appealing simplicity, the elastic network model (ENM) has been widely accepted and applied to study many molecular motion problems, such as the molecular mechanisms of chaperonin GroEL-GroES function, allosteric changes in hemoglobin, ribosome motions, motor-protein motions, and conformational changes in general. In this dissertation, the ENM is employed to study various protein dynamics problems, and its validity is also examined by comparing with experimental data. First, we apply principal component analysis (PCA) to identify the essential protein motions from multiple structures (X-ray, NMR and MD) of the HIV-1 protease. We find significant similarities between the first few ...


Investigation Of The Peptide-Lipid Interactions Of A Beta-Hairpin Antimicrobial Peptide Using Solid-State Nmr, Rajeswari Mani Jan 2007

Investigation Of The Peptide-Lipid Interactions Of A Beta-Hairpin Antimicrobial Peptide Using Solid-State Nmr, Rajeswari Mani

Retrospective Theses and Dissertations

Solid-state NMR (SSNMR) has gained importance as a versatile tool to elucidate the structure and function of many chemical and biological molecules. In this thesis, we have used SSNMR to study the interactions of an antimicrobial peptide (AMP), Protegrin-1 (PG-1) with membranes of varying lipid composition. Based on our studies we have proposed a model for the mechanism of action of PG-1 with two different lipid membranes. PG-1 is a disulfide-linked beta-sheet peptide with broad-spectrum antimicrobial activities. Similar to many AMPs, it selectively disrupts the anionic membranes of microbial cells but leaves the cholesterol-rich zwitterionic mammalian cell membranes intact.;Studying ...


Advanced Detection And Separation Methods: Developments In Surface-Enhanced Raman Scattering Readout Immunoassays And Electrochemically Modulated Liquid Chromatography, Betsy Jean Yakes Jan 2007

Advanced Detection And Separation Methods: Developments In Surface-Enhanced Raman Scattering Readout Immunoassays And Electrochemically Modulated Liquid Chromatography, Betsy Jean Yakes

Retrospective Theses and Dissertations

This dissertation explores the use of novel detection methods for biological and chemical components commonly found in the environment. It encompasses two techniques: surface-enhanced Raman scattering (SERS) and electrochemically modulated liquid chromatography (EMLC).;Immunoassays using SERS as a readout tool have been developed in this laboratory and have shown low levels of detection (i.e., pico- to femtomolar and single binding event detection) for disease and biowarfare agents. This thesis seeks to further the performance of this platform for bacteria detection and explore strategies to increase the SERS response. Specifically, the first section of this dissertation focuses on the detection ...


A Penalty Function Method For Constrained Molecular Dynamics , Ajith Gunaratne Jan 2006

A Penalty Function Method For Constrained Molecular Dynamics , Ajith Gunaratne

Retrospective Theses and Dissertations

We propose a penalty-function method for constrained molecular dynamic simulation by defining a quadratic penalty function for the constraints. The simulation with such a method can be done by using a conventional, unconstrained solver only with the penalty parameter increased in an appropriate manner as the simulation proceeds. More specifically, we scale the constraints with their force constants when forming the penalty terms. The resulting force function can then be viewed as a smooth continuation of the original force field as the penalty parameter increases. The penalty function method is easy to implement and costs less than a Lagrange multiplier ...


Synthesis Of Tetrasubstituted Olefins And Aryl Ketones Via Carbopalladation Of Alkynes And Nitriles , Chengxiang Zhou Jan 2006

Synthesis Of Tetrasubstituted Olefins And Aryl Ketones Via Carbopalladation Of Alkynes And Nitriles , Chengxiang Zhou

Retrospective Theses and Dissertations

Palladium-catalyzed reactions are versatile methods for carbon-carbon bond formation due to their generality and ability to tolerate a wide range of important organic functional groups. Developing novel Palladium-catalyzed reactions has therefore been of great interest to synthetic chemists for years;The regio- and stereoselective synthesis of tetrasubstituted olefins is a long-pursuing challenge for synthetic chemists. A multi-component reaction route is ideal to generate various tetrasubstituted olefins in a very concise manner and should be highly desirable for applications in combinatorial chemistry. A highly efficient, regio- and stereoselective route to tetrasubstituted olefins has been developed by the Pd-catalyzed three-component reaction of ...


A Modular Data Analysis Pipeline For The Discovery Of Novel Rna Motifs , Justin Schonfeld Jan 2006

A Modular Data Analysis Pipeline For The Discovery Of Novel Rna Motifs , Justin Schonfeld

Retrospective Theses and Dissertations

This dissertation presents a modular software pipeline that searches collections of RNA sequences for novel RNA motifs. In this case the motifs incorporate elements of primary and secondary structure. The motif search pipeline breaks up sets of RNA sequences into shortened segments of RNA primary sequence. The shortened segments are then folded to obtain low energy secondary structures. The distance estimation module of the pipeline then calculates distances between the folded bricks, and then analyzes the resulting distance matrices for patterns;An initial implementation of the pipeline is applied to synthetic and biological data sets. This implementation introduces a new ...


Bayesian Recombination Detection Modeling And Application, Fang Fang Jan 2006

Bayesian Recombination Detection Modeling And Application, Fang Fang

Retrospective Theses and Dissertations

As a key evolutionary process, recombination shapes the genetic structure of virus populations. The increased availability of virus sequences provides a chance to study virus recombination through molecular data. Many statistical methods have been developed, and a lot of the methods are phylogenetic-based. My research focuses on recombination modeling and data analysis;I first apply an existing phylogenetic-base method, Bayesian dual change-point model (DMCP), to investigate the role of representative data types for recombination study. We conclude that consensus sequences are an all-around robust representative of virus genotypes. Using consensus data we study recombination of all full-length hepatitis B virus ...


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 ...


Distance-Based Nmr Structure Determination And Refinement, Feng Cui Jan 2005

Distance-Based Nmr Structure Determination And Refinement, Feng Cui

Retrospective Theses and Dissertations

Protein structures play a pivotal role in understanding protein functions. X-ray crystallography and nuclear magnetic resonance spectroscopy (NMR) are two main experimental approaches for protein structure determination. The structures determined by NMR are not as accurate as those by X-ray crystallography in general, due to limited distance data (e.g. NOEs) that can be generated from NMR experiments. The NMR modeling algorithms are not well developed either, to produce high-quality structures with desired accuracy and efficiency. To address the NMR modeling issues, a so-called geometric build-up approach for NMR modeling has been developed, which remarkably reduces computing time in determining ...


Identification Of Interface Residues Involved In Protein-Protein And Protein-Dna Interactions From Sequence Using Machine Learning Approaches , Changhui Yan Jan 2005

Identification Of Interface Residues Involved In Protein-Protein And Protein-Dna Interactions From Sequence Using Machine Learning Approaches , Changhui Yan

Retrospective Theses and Dissertations

Identification of interface residues involved in protein-protein and protein-DNA interactions is critical for understanding the functions of biological systems. Because identifying interface residues using experimental methods cannot catch up with the pace at which protein sequences are determined, computational methods that can identify interface residues are urgently needed. In this study, we apply machine-learning methods to identify interface residues with the focus on the methods using amino acid sequence information alone. We have developed classifiers for identification of the residues involved in protein-protein and protein-DNA interactions using a window of primary sequence as input. The classifiers were evaluated using both ...


Probing Carbohydrate Biocatalysis Through The Use Of Electrospray Ionization Mass Spectrometry And Isothermal Titration Calorimetry , Corbin James Zea Jan 2005

Probing Carbohydrate Biocatalysis Through The Use Of Electrospray Ionization Mass Spectrometry And Isothermal Titration Calorimetry , Corbin James Zea

Retrospective Theses and Dissertations

Electrospray ionization mass spectrometry,(ESI-MS)-based assays have been newly developed to study three classes of enzymes (sugar nucleotidyltransferases, glycosyltransferases, and phosphorylases) from the three distinct families of life: archaea, eukaryotes, and prokaryotes. These three classes of enzymes play vital roles in carbohydrate storage, degradation and synthesis. The sugar nucleotidyltransferases from Escherichia coli and yeast that biosynthesize UDP-glucose and ADP-glucose respectively were studied using the first ESI-MS assay. Nonlinear regression of the kinetic data was comparable to those determined from the traditional UDP-glucose dehydrogenase coupled assay. This technique allowed us to determine that the yeast sugar nucleotidyltransferase has one binding ...


Cell Envelope Constituents Of Pseudomonas Putida Contributing To Growth And Survival In Low-Water-Content Habitats , Martinus Franciscus Maria Van De Mortel Jan 2005

Cell Envelope Constituents Of Pseudomonas Putida Contributing To Growth And Survival In Low-Water-Content Habitats , Martinus Franciscus Maria Van De Mortel

Retrospective Theses and Dissertations

The ability of bacteria to respond to the ever changing environmental conditions they encounter requires the utilization of a broad range of colonization and survival strategies. One of the most important and probably least understood factors determining bacterial activity in terrestrial habitats is water availability. The goal of this dissertation research was to identify traits that contribute to maintaining a functional cell envelope when cells are dehydrated, which will help us to assess the scope of physiological changes necessary for growth in low-water-content habitats. The primary objective was to identify genes that are specifically regulated by dehydration (matric stress), and ...


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 ...


Molecular And Chemical Characterization Of Genes Involved In Maize Cuticular Wax Biosynthesis , M. Ann D. N. Perera Jan 2005

Molecular And Chemical Characterization Of Genes Involved In Maize Cuticular Wax Biosynthesis , M. Ann D. N. Perera

Retrospective Theses and Dissertations

The primary surfaces of the arial parts of plants, and the surfaces of reproductive organs are covered by an extra cellular layer called the cuticle. The cuticle provides the foremost protection to the plant in order to adapt to the terrestrial environment. The cuticle composed of a biopolymer (cutin), which is embedded in a coating of cuticular waxes. Understanding the biochemical, genetic and physiological mechanisms for the biosynthesis of these cuticular waxes is relatively poor. This body of work has established methods for the chemical analysis of the cuticular waxes of maize plants. I have used these methods to chemically ...


Exploring Statistical Methods For Analysis Of Microarray Data , Tanzy Mae Tallapoosa Paz Love Jan 2005

Exploring Statistical Methods For Analysis Of Microarray Data , Tanzy Mae Tallapoosa Paz Love

Retrospective Theses and Dissertations

The expansion of molecular biology in recent years has created an increasing amount of data and interest in specific tools to analyze them. Much of these data come from a class of high-throughput technology that measures hundreds or thousands of variables at the same time. One such high-throughput technology currently in use is microarray technology. The three major objectives in expression analysis are data preprocessing, identifying differential expression, and grouping genes by common behavior. Extracting the useful information on gene expression from the available output is not trivial. The data collection process is quite noisy in that non-biological bias may ...


Mesoporous Silica Nanomaterials For Applications In Catalysis, Sensing, Drug Delivery And Gene Transfection , Daniela Rodica Radu Jan 2004

Mesoporous Silica Nanomaterials For Applications In Catalysis, Sensing, Drug Delivery And Gene Transfection , Daniela Rodica Radu

Retrospective Theses and Dissertations

The central theme of this dissertation is represented by the versatility of mesoporous silica nanomaterials in various applications such as catalysis and bio-applications, with main focus on biological applications of Mesoporous Silica Nanospheres (MSN). The metamorphosis that we impose to these materials from catalysis to sensing and to drug and gene delivery is detailed in this dissertation. First, we developed a synthetic method that can fine tune the amount of chemically accessible organic functional groups on the pores surface of MSN by exploiting electrostatic and size matching between the cationic alkylammonium head group of the CTAB surfactant and various anionic ...


Multifunctional Mesoporous Silica Nanospheres For Biosensor, Stimuli-Responsive Controlled-Release Drug Delivery Carriers And Gene Transfection Vectors , Cheng-Yu Lai Jan 2004

Multifunctional Mesoporous Silica Nanospheres For Biosensor, Stimuli-Responsive Controlled-Release Drug Delivery Carriers And Gene Transfection Vectors , Cheng-Yu Lai

Retrospective Theses and Dissertations

Structurally well-defined mesoporous silica materials with tunable pore size and narrow pore-size distribution have attracted much attention for their potential applications in sensing, drug delivery and gene transfer. A series of mesoporous silica nanosphere-based (MSN) nano-devices were synthesized and utilized for the aforementioned applications.;For sensing application, we provide a first example in utilization of a multi-functionalized mesoporous silica material to selectively detect dopamine. A second application, rooted in this work, is the selective detection of amino-containing neurotransmitters under physiological condition.;The drug delivery applications have been built around a controlled release drug delivery device. In the original conception, the ...


A Threading Approach To Protein Structure Prediction: Studies On Tnf-Like Molecules, Rev Proteins, And Protein Kinases , Yungok Ihm Jan 2004

A Threading Approach To Protein Structure Prediction: Studies On Tnf-Like Molecules, Rev Proteins, And Protein Kinases , Yungok Ihm

Retrospective Theses and Dissertations

The main focus of this dissertation is the application of the threading approach to specific biological problems. The threading scheme developed in our group targets incorporating important structural features necessary for detecting structural similarity between the target sequence and the template structure. This enables us to use our threading method to solve problems for which sequence-based methods are not very much useful. We applied our threading method to predict the three-dimensional structures of lentivirus (EIAV, HIV-1, FIV, SIV) Rev proteins. Predicted structures of Rev proteins suggest that they share a structural similarity among themselves (four-helix bundle). Also, the threading approach ...


Protein-Protein Interaction And Electron Transfer: Case Of Cytochrome F And Cytochrome C6 , Tijana Žarković Grove Jan 2004

Protein-Protein Interaction And Electron Transfer: Case Of Cytochrome F And Cytochrome C6 , Tijana Žarković Grove

Retrospective Theses and Dissertations

We used photo-induced reaction as a tool to look to explore dynamics of the protein-protein interaction between cytochrome f and cytochrome c6 from C. reinhardtii. In our studies of electron transfer between 3Zncyt c6 and cyt f(III) we discovered two distinct intracomplex processes corresponding to electron transfer within diprotein complexes termed persistent and transient. The overall reaction remained biphasic and the rate constants for both processes were invariant to the change of ionic strength within the studied interval. The docking of these proteins is due to strong hydrophobic interaction slightly augmented by weak electrostatic attraction. We used covalent cross-linking ...


Molecular Marker Analysis Of Population Genetic Structure And Progress From Reciprocal Recurrent Selection In Two Iowa Maize (Zea Mays L) Populations , Lori Lynn Hinze Jan 2003

Molecular Marker Analysis Of Population Genetic Structure And Progress From Reciprocal Recurrent Selection In Two Iowa Maize (Zea Mays L) Populations , Lori Lynn Hinze

Retrospective Theses and Dissertations

Studies of the genetic structure of the Iowa Corn Borer Synthetic #1 (CB) and Iowa Stiff Stalk Synthetic (SS) maize populations are of particular significance because they serve as the model on which development of modern commercial hybrids are based. These populations are part of a reciprocal recurrent selection breeding strategy. With this strategy, plants from one population are crossed to plants from the opposite population (i.e. forming hybrids). These hybrids are tested, and the best ones are chosen. The plants crossed to form the chosen hybrids are identified and used to form the next generation in each population ...


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 ...


Complexes Of Palladium(Ii) And Platinum(Ii) As Synthetic Proteases , Nebojša M. Milović Jan 2002

Complexes Of Palladium(Ii) And Platinum(Ii) As Synthetic Proteases , Nebojša M. Milović

Retrospective Theses and Dissertations

Selective cleavage of proteins is a common procedure in many biochemical applications ranging from standard protein sequencing to novel methods in proteomics and bioengineering. Few enzymes and synthetic reagents are available for this important task, but new chemical reagents with improved efficiency and adjustable selectivity are highly desired. Complexes of palladium(II) and platinum(II), two chemically similar transition-metal ions, are new reagents for selective cleavage of peptides and proteins. The cleavage by Pd(II) complexes, such as [Pd(H2O)4]2+ or cis-[Pd(en)(H 2O)2]2+, consistently occurs in weakly acidic aqueous solutions at the amide ...


Photophysics And Light Induced Photobiology Of Antiviral And Antitumor Agents, Hypericin And Hypocrellin , Jaehun Park Jan 2001

Photophysics And Light Induced Photobiology Of Antiviral And Antitumor Agents, Hypericin And Hypocrellin , Jaehun Park

Retrospective Theses and Dissertations

The dissertation mainly focuses on the excited-state photophysics and the light-induced biological activity of hypericin and its analogs.;Femtosecond laser technology has provided the opportunity to investigate the rapid dynamics of these molecules. Fluorescence upconversion measurements, which monitor only emission from the fluorescent singlet state, demonstrate that hexamethoxy hypericin, which possesses no labile protons, has an instantaneous rise time for its transient response. On the other hand, hypericin shows a clear 10-ps rise time. This confirms excited-state H-atom transfer as the primary photophysical process in hypericin.;Femtosecond transient absorption spectroscopy technique is used to determine if excited state H-atom transfer ...


Genetic Variation And Evolution Of Equine Infectious Anemia Virus Rev Quasispecies During Long Term Persistent Infection , Prasith Baccam Jan 2000

Genetic Variation And Evolution Of Equine Infectious Anemia Virus Rev Quasispecies During Long Term Persistent Infection , Prasith Baccam

Retrospective Theses and Dissertations

Genetic variation has been observed in many viruses. Viruses that carry their genetic information in the form of RNA exhibit high mutation rates because the viral polymerase lacks proof-reading mechanisms commonly found in DNA polymerase complexes. The combination of high mutation rates, small genome size, and high replication rates results in a population of closely related viral genotypes, which are commonly referred to as a quasispecies. A consequence of the genetic variation in viruses is possible variation in viral phenotype of the quasispecies population. Furthermore, changes in viral phenotype may be a biologically important factor in progression of disease. Here ...


Interactions And Electron-Transfer Reactions Between Metalloproteins , Milan Miroslav Crnogorac Jan 2000

Interactions And Electron-Transfer Reactions Between Metalloproteins , Milan Miroslav Crnogorac

Retrospective Theses and Dissertations

Electron-transfer reactions are essential for life. Because metalloproteins are involved in electron transport in the cell, it is important to understand the factors that affect recognition, interaction, and reactions of these electron carriers. Cytochrome c is well-characterized electron-carrier protein. The heme protein cytochrome c and the blue-copper protein plastocyanin are well suited for kinetic and mechanistic studies since their structures are known in detail;We investigated the effects of site-directed mutations and viscosity on rate-limiting rearrangement within the complex of cytochrome c and plastocyanin and identified the reactive configuration of the complex. In the reactive configuration of the complex cytochrome ...


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 ...


Two Dimensional Models Of Tumor Angiogenesis , Serdal Pamuk Jan 2000

Two Dimensional Models Of Tumor Angiogenesis , Serdal Pamuk

Retrospective Theses and Dissertations

Angiogenesis, the formation of new capillaries from pre-existing vessels, is essential for tumor progression. It is critical for the growth of primary cancers. In this thesis we present a new approach to angiogenesis, based on the theory of reinforced random walks, coupled with a Michaelis-Menten type mechanism. This views the endothelial cell receptors as the catalyst for transforming angiogenic factor into proteolytic enzyme in order to model the first stage. In our model we use a curvature-induced proliferation term for the endothelial cell equation. Our numerical results indicate that the proliferation of endothelial cells is high at the tip. Also ...


Primary Photoprocesses Of Light-Activated Antiviral And Antitumor Agents, Hypericin And Hypocrellin , Alexandre V. Smirnov Jan 1999

Primary Photoprocesses Of Light-Activated Antiviral And Antitumor Agents, Hypericin And Hypocrellin , Alexandre V. Smirnov

Retrospective Theses and Dissertations

The dissertation focuses on the ultrafast primary photoprocesses of the title anti-viral and anti-cancer agents, whose activity depends on light which is also accompanied by photoacidification in vesicles and living cells;By complementing the techniques of time-resolved absorption spectroscopy with those of fluorescence upconversion and applying them to hypericin, hypocrellin A and B, and their methylated analogs that are unable to execute proton transfer, it was demonstrated that intramolecular excited-state hydrogen atom transfer is a dominant primary nonradiative process;For hypocrellin A in viscous solvents such as octanol and ethylene glycol, an absorption transient of ∼10-ps duration, similar to the ...


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 ...


Application Of Spectral Hole Burning To The Study Of In Vitro Cellular Systems , Nebojsa Milanovich Jan 1999

Application Of Spectral Hole Burning To The Study Of In Vitro Cellular Systems , Nebojsa Milanovich

Retrospective Theses and Dissertations

The high resolution spectroscopic technique of nonphotochemical hole burning (NPHB) was applied to the study of in vitro cellular systems. Suspensions of two well-characterized cell lines were used for these studies: (1) MCF-10F cells, a normal human breast epithelial cell line, and (2) MCF-7 cells, a human breast adenocarcinoma cell line. Both cell lines were stained with the dye aluminum phthalocyanine tetrasulfonate (APT) and prepared for spectroscopic study at liquid helium temperatures. Routinely measured hole burning parameters were obtained for the two cell types and compared in order to differentiate between physical properties of normal and cancer cells;A comparison ...