Biomedical subjects

Andras Guttman

Publications and source records attributed to Andras Guttman.

6 recordsLinked to original sources

PubMed2006

Material-enhanced laser desorption/ionization (MELDI)--a new protein profiling tool utilizing specific carrier materials for time of flight mass spectrometric analysis.

Over the past couple of years, proteomics pattern analysis has emerged as an effective method for the early diagnosis of diseases such as ovarian, breast, or prostate cancer, without identification of single biomarkers. MALDI-TOF MS, for example, offers a simple approach for fast and reliable protein profiling, especially by using carrier materials with various physical and chemical properties, in combination with a MALDI matrix. This approach is referred to as material-enhanced laser desorption/ionization (MELDI). In this paper, we report the development and application of derivatized carrier materials [cellulose, silica, poly(glycidyl methacrylate/divinylbenzene) (GMA/DVB) particles, and diamond powder] for fast and direct MALDI-TOF MS protein profiling. The applicability of MELDI for rapid protein profiling was evaluated with human serum samples. These carriers, having various hydrophobicities, resulted in characteristic mass fingerprints, even if all materials were derivatized with iminodiacetic acid (IDA) to yield an immobilized metal affinity chromatography (IMAC) functionality. Our study demonstrates that analyzing complex biological samples, such as human serum, by employing different MELDI carrier materials yielded type- and size-dependent performance variation.

Indicators and Reagents↗

PubMed2005

Combinatorial natural products: from cloning to analysis.

Medicinal compounds from plants represent one of the largest and most diverse groups of plant secondary metabolites. The advent of advanced bioinformatics tools and modern genetic technology allowed for manipulation of biosynthetic pathways with the potential of generating novel chemical entities. First, public databases of secondary metabolite related enzymes were interrogated to identify relevant plant genes from vinca rosea (Catharanthus roseus) and other species. Genes of interest were tested after cloning by transfection into tobacco cell cultures using DNA viral vectors. The biosynthetic enzymes coded by these genes were over-expressed in the host. Automated solvent extraction procedure was employed to extract secondary metabolites from plant leaf tissues and transfected tobacco cell culture samples. The composition of the extracts was analyzed by state of the art bioanalytical methods such as high performance liquid chromatography and capillary electrophoresis to monitor changes in secondary metabolite patterns.

Chromatography, High Pressure Liquid↗

PubMed2004

DNA profiling by capillary array electrophoresis with non-covalent fluorescent labeling.

Increasing need for large-scale DNA profiling necessitated the development of automated electrophoresis based methods enabling rapid, high performance analysis of nucleic acids in a wide molecular-mass range. In this paper, we report on the adaptation of a commercial 96-capillary array electrophoresis (CAE) instrument for high-throughput DNA fragment analysis and the evaluation of the effects of different non-covalent DNA staining dyes on separation efficiency. The applicability of different color internal fluorescent standards is shown with mathematical spectral overlap correction algorithms. Large-scale quality control assessment of oligonucleotide probes using non-covalent fluorophore labeling is also demonstrated. The method requires small sample amounts, offers automation and quantification capabilities to accommodate modern biotechnology industry needs.

Algorithms↗

PubMed2004

Large-scale carbohydrate analysis by capillary array electrophoresis: part 1. Separation and scale-up.

A 96-capillary array electrophoresis (CAE) instrument has been adapted for large-scale mono- and oligosaccharide analysis and characterization. Operational protocols and data processing tools have been developed to optimize the CAE system for this application. Effects of different additives to the running buffer on efficiency and capillary-to-capillary performance reproducibility have been studied.

Buffers↗

PubMed2004

Large-scale carbohydrate analysis by capillary array electrophoresis: part 2. Data normalization and quantification.

Automated 96-capillary array electrophoresis (CAE) methodology described in the first part of the present work offered large-scale high-performance profiling of oligo- and monosaccharides to fulfill the needs of bioindustrial laboratories. Sensitivity at low nanomolar concentration, good resolving power and reliability achieved in the experiments is invaluable for monitoring reaction products from enzymatic polysaccharide digestion with numerous applications in agricultural, chemical and food industries. In addition to optimization of mono- and oligosaccharide separations in CAE system and necessary operational protocol modifications, capillary-to-capillary and run-to-run variation in migration time and signal intensity necessitated development of data normalization tools. Internal fluorescent standards have been incorporated into the analysis aiding migration time normalization and CAE trace alignment. Data processing, visualization, and programming tools have been developed along with quantification approaches.

Biotechnology↗

PubMed2003

Differential gene expression analysis by micro-preparative capillary gel electrophoresis.

Differential display analysis by cDNA fractionation, collection of differentially expressed fractions of interests and their downstream characterization is demonstrated. cDNA pools from two strains of Cochliobolus heterostrophus fungus were generated by specific restriction digestion and selective ligation. Micropreparative separation and isolation of differentially expressed transcript representatives were accomplished by high-performance capillary gel electrophoresis. The collected individual DNA molecules were polymerase chain reaction amplified and sequenced to create expressed sequence tags for the genes of interests. High resolving power and sensitivity of capillary gel electrophoresis enabled fast and automated processing of minute amounts of cDNA samples with high precision.

Base Sequence↗