Single DNA Molecules (single + dna_molecule)

Distribution by Scientific Domains


Selected Abstracts


ChemInform Abstract: Photobleaching of Asymmetric Cyanines Used for Fluorescence Imaging of Single DNA Molecules.

CHEMINFORM, Issue 49 2001
Claire Kanony
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


Cover Picture: Electrophoresis 14/2008

ELECTROPHORESIS, Issue 14 2008
Article first published online: 23 JUL 200
Issue 14 is a regular issue including an Emphasis Section offering a series of 9 papers on ,Microfluidics and Miniaturization". These 9 research papers report on various topics including studying single DNA molecules, selective release of intracellular molecules on the single cell level, isoelectric focusing of proteins in an ordered micropillar array, sample stream focusing in a microchip, integrated microfluidic system for sensing infectious viral disease, EOF in annulus and rectangular channels, confinement effects on monolith morphology, accumulation and filtering of nanoparticles in microchannels, and carbon nanotubes disposable detectors. [source]


Determination of haplotypes from single DNA molecules: a method for single-molecule barcoding,,

HUMAN MUTATION, Issue 9 2007
Ming Xiao
Abstract Determining the haplotypes in a diploid individual is a major technical challenge in genetic studies of human complex traits. Here we report a method of molecular haplotyping by directly imaging multiple polymorphic sites on individual DNA molecules simultaneously. DNA fragments amplified by long-range PCR were labeled with fluorescent dyes at each polymorphic site using a modified gap-filled padlock probe ligation approach. The labeled DNA molecules were then stretched into linear form on a functionalized glass surface and imaged with multicolor total internal reflection fluorescence (TIRF) microscopy. By determining the colors and positions of the fluorescent labels with respect to the backbone at polymorphic sites, the haplotype can be inferred accurately, in a manner similar to reading a barcode, even when the DNA fragments are not fully labeled. The feasibility of this technology is demonstrated by the determination of the haplotype of a 9.3-kbp DNA fragment containing four SNPs. Hum Mutat 28(9), 913,921, 2007. Published 2007 Wiley-Liss, Inc. [source]


Stretching single DNA molecules to demonstrate high-force capabilities of holographic optical tweezers

JOURNAL OF BIOPHOTONICS, Issue 4 2010
Arnau Farré
Abstract The well calibrated force-extension behaviour of single double-stranded DNA molecules was used as a standard to investigate the performance of phase-only holographic optical tweezers at high forces. Specifically, the characteristic overstretch transition at 65 pN was found to appear where expected, demonstrating (1) that holographic optical trap calibration using thermal fluctuation methods is valid to high forces; (2) that the holographic optical traps are harmonic out to >250 nm of 2.1 ,m particle displacement; and (3) that temporal modulations in traps induced by the spatial light modulator (SLM) do not affect the ability of optical traps to hold and steer particles against high forces. These studies demonstrate a new high-force capability for holographic optical traps achievable by SLM technologies. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


On/off switching on polymer conformation

MACROMOLECULAR SYMPOSIA, Issue 1 2003
Kenichi Yoshikawa
Abstract The manner of folding transition from elongated coil to compact globule of single polymer chain is discussed. Based on theoretical consideration, it is argued the semi-flexible polymer chain exhibits large discrete transition on the level of individual single chains, whereas the transition looks continuous, or cooperative, on the ensemble of chains. As the experimental verification, in the present article thermodynamic and kinetic aspects of folding transition of single giant DNA molecules are described. It is shown that rich variety of nano-ordered structures are obtained from single DNA molecules through suitable setup of the experimental conditions. The stability of such nano-structures generated from single polymer chain is discussed in relation to the ordered compact structure with large number of chains in semi-dilute and concentrated polymer solutions. [source]


Direct Visualization of Abasic Sites on a Single DNA Molecule Using Fluorescence Microscopy,

PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 2 2002
Tamaki Hirose
ABSTRACT A new method was developed to allow direct visualization of damaged sites on individual DNA molecules. Fluorescence in situ hybridization on extended DNA molecules was modified to detect a single abasic site. Abasic sites were specifically labeled with a biotinylated aldehyde-reactive probe and fluorochrome-conjugated streptavidin. The light emitted by a single fluorochrome,DNA complex was calibrated. The number of abasic sites on the DNA molecule was estimated by counting each fluorochrome,DNA complex. The present study directly visualized and characterized the abasic sites of single DNA molecules. [source]