Cell specific gene silencing effects of antisense oligodeoxynucleotide (AS-ODN), synthetic small interfering RNA (siRNA-S), and siRNA expressing plasmid (siRNA-P) were comparatively evaluated. Poly(ethylenimine) (PEI) and PEI-graft-poly(ethylene glycol)-folate (PEI-PEG-FOL) conjugate were used to form nanosized polyelectrolyte complexes with the above three nucleic acids coding for inhibition of green fluorescent protein (GFP) ...

Therapeutic application of siRNA requires delivery to the correct intracellular location, to interact with the RNAi machinery within the target cell, within the target tissue responsible for the pathology. Each of these levels of targeting poses a significant barrier. To overcome these barriers several strategies have been developed, such as ...

BACKGROUND: Development of a practical gene point-of-care testing device (g-POCT device) requires innovative detection methods for demonstrating the results of the gene amplification reaction without the use of expensive equipment. We have studied a new method for the sequence-specific visual detection of minute amounts of nucleic acids using precipitation reaction ...

The distributions of Brönsted acidic protons and their acid strengths in zeolite H-MCM-22 have been characterized by density functional theory (DFT) calculations as well as magic angle spinning (MAS) NMR experiments. The embedded scheme (ONIOM) that combines the quantum mechanical (QM) description of active sites and semiempirical AM1 treatment of ...

The hydroxyl at the C-3 of cholic acid was converted to an amino group, and the resulting amino-functionalized cholic acid was used as a monomer to prepare amide-linked oligomeric cholates. These cholate oligomers fold into helical structures with nanometer-sized hydrophilic internal cavities in solvent mixtures consisting of mostly nonpolar solvents ...

We show with atomic force microscopy that thioctic acid, a spatially constrained system with two sulfur linkages to gold, is less stable to tensile stress than a thiolate with a single attachment to gold. The force required to remove the dithiolate-linked thioctic acid was 0.31+/-0.13 nN, whereas the force required ...

Winter-induced inhibition of photosynthesis in Scots pine (Pinus sylvestris L.) needles is accompanied by a 65% reduction of the maximum photochemical efficiency of photosystem II (PSII), measured as Fv/Fm, but relatively stable photosystem I (PSI) activity. In contrast, the photochemical efficiency of PSII in bark chlorenchyma of Scots pine twigs ...

Iso-stearic acid, a short, stubby compound with branched, methylated tails has been shown to have high solubility in carbon dioxide. Tail solvation by carbon dioxide makes iso-stearic acid a good choice for use as a ligand to sterically stabilize metallic nanoparticles. Iso-stearic acid coated silver nanoparticles have been stably dispersed ...

Dendrimers have unique molecular architectures and properties that make them attractive materials for the development of nanomedicines. Key properties such as defined architecture and a high ratio of multivalent surface moieties to molecular volume also make these nanoscaled materials highly interesting for the development of synthetic (non-viral) vectors for therapeutic ...

Conformational and thermal behavior of self-assembled structures of three phosphonic acids, OPA (octadecylphosphonic acid), TPA (tetradecylphosphonic acid), and OcPA (octylphosphonic acid), with different alkyl chain lengths are investigated and compared. The orientation of self-assembled bilayers depends on whether the substrate is nonpolar (graphite) or polar (mica). For nonpolar substrates, bilayers ...

During infection or tissue damage, the innate immune system detects and responds to nucleic acids released from pathogens or damaged host cells. Accumulating evidence has showed that specific sequences, modifications or structures of nucleic acids influence their immunomodulatory activities. Resulting innate immune modulations are regulated by Toll-like receptor (TLR)-dependent or ...

The cause of the strong non-photochemical fluorescence quenching was examined in maize (Zea mays L.) plants that were treated with lincomycin during the 72 h period of greening. They were deficient in core complexes but seemed to contain the full complement of antennae. The following results were obtained: (1) High ...

Molecular beacons are single-stranded nucleic acid structures with a terminal fluorophore and a distal, terminal quencher. These molecules are typically used in real-time PCR assays, but have also been conjugated with solid matrices. This unit describes protocols related to molecular beacon-conjugated beads (BeadCons), whose specific hybridization with complementary target sequences ...

Since the discovery of the first natural ribozyme more than 20 years ago, it has become clear that nucleic acids are not only the static depository of genetic information, but also possess intriguing catalytic activity. The number of reactions catalyzed by engineered nucleic acid enzymes is growing continuously. The versatility ...

Downward fluxes of nucleic acids adsorbed onto settling particles play a key role in the supply of organic phosphorus and genetic material to the ocean interior. However, information on pelagic-benthic coupling, diagenesis, and processes controlling nucleic acid preservation in deep-sea sediments is practically nonexistent. In this study, we compared nucleic ...

The need for nucleic acid based diagnostic tests has increased enormously in the last few years. On the one hand, this has been stimulated by the discovery of new hereditary genetic disease loci following the completion of the Human Genome Project, but also by the presence of new rapidly spreading ...

The use of power ultrasound in enhancing diffusion rate in various chemical as well as physical processes is gaining in importance. The influence of power ultrasound in the leather dyeing process on enhancing the penetration of dye through the leather matrix was studied. The penetration of dye through a leather ...

GST fusion proteins of the six gene products from RNAs 2,3 and 4 of the tenuivirus, Rice stripe virus (RSV), were used to study the nucleic acid binding activities in vitro. Three of the proteins, p3, pc3 and pc4, bound both single- and double-stranded cDNA of RSV RNA4 and also ...

Nucleic acid amplification techniques have revolutionised diagnostic and research industries. Current technologies that allow the detection of amplification in real-time are fast becoming industry standards, particularly in a diagnostic context. In this review, we describe and explore the application of numerous real-time detection chemistries and amplification techniques for pathogen detection ...

We report biological changes at several UK Acid Waters Monitoring Network lakes and streams that are spatially consistent with the recovery of water chemistry induced by reductions in acid deposition. These include trends toward more acid-sensitive epilithic diatom and macroinvertebrate assemblages, an increasing proportional abundance of macroinvertebrate predators, an increasing ...

A nucleic acid extraction system that can handle small numbers of specimens with a short test turnaround time and short hands-on time is desirable for emergent testing. We performed a comparative validation on three systems: the MagNA Pure compact system (Compact), the NucliSens miniMAG extraction instrument (miniMAG), and the BioRobot ...

A new quantitative method for micro amounts of nucleic acids in aqueous solution is proposed using Eu3+-benzoylacetone (BA) complex as fluorescent probe in the presence of cetyltrimethyl-ammonium bromide (CTMAB). Under the optimum condition, the ratio of the fluorescence intensities with and without nucleic acids is proportional to the concentration of ...

We have used a compartmentalized in vitro selection method to directly select for ligase ribozymes that are capable of acting on and turning over separable oligonucleotide substrates. Starting from a degenerate pool, we selected a trans-acting variant of the Bartel class I ligase which statistically may have been the only ...

Formalin-fixed, paraffin-embedded specimens typically provide molecular biologists with low yields of extractable nucleic acids that exhibit extensive strand cleavage and covalent modification of nucleic acid bases. This study supports the idea that these deleterious effects are promoted by the first step in formalin-fixed tissue processing--i.e., tissue dehydration with a graded ...

BACKGROUND: A number of formats for nucleic acid hybridization have been developed to identify DNA and RNA sequences that are involved in cellular processes and that aid in the diagnosis of genetic and infectious diseases. METHODS: The introduction of hybridization probes with interactive fluorophore pairs has enabled the development of ...

UV light irradiation effect on the structural transformation in a self-assembled monolayer of 4-(amyloxy)cinnamic acid (AOCA) on Au(111) has been investigated by using electrochemical scanning tunneling microscopy (ECSTM), cyclic voltammetry, and infrared (IR) spectroscopy. A well-defined 4-(amyloxy)cinnamic acid adlayer with a (4 x 11) symmetry was first prepared on Au(111). ...

Diversity of prion strains was attributed to an elusive nucleic acid, yet a search spanning nearly two decades has failed to identify a prion-specific polynucleotide. In our search for a prion-specific nucleic acid, we analyzed nucleic acids in purified fractions from the brains of Syrian hamsters infected with Sc237 prions. ...

Delivery of oligonucleotides has been a major impediment in the development of nucleic acid based drugs. In this report, we show that neomycin, an aminoglycoside antibiotic, when combined with a cationic lipid preparation such as DOTAP, enhances transfection efficiency of both reporter plasmids and oligonucleotides and results in a significant ...

A neutral amphiphile derived from uridine featuring two oleyl chains and one glucose for DNA binding was prepared using a convenient four-step synthetic route. The nucleic acid binding capabilities of this amphiphile were investigated by UV-vis, quasi-elastic light scattering (QELS), transmission electronic microscopy (TEM), gel electrophoresis, 31P NMR, IR, and ...

Multiplexed and quantitative analysis of nucleic acid sequences in complex mixtures is essential in various applications of microbiological research. We have developed a method based on solution hybridization between biotinylated nucleic acid targets and multiple fluorophore-labeled oligonucleotide probes of distinct sizes. The biotin-nucleic acid-probe complexes are captured on magnetic streptavidin-coated ...

The interaction of xylenol orange (XO) and nucleic acids in the presence of cetyltrimethylammonium bromide (CTMAB) in aqueous solution has been studied by a resonance light-scattering (RLS) technique with a common spectrofluorometer. In hexamethylenetetramine (HMTA) buffer (pH7.30), XO and nucleic acids react with cetyltrimethylammonium bromide to form large particles of ...

Real-time nucleic acid sequence-based amplification (NASBA) using molecular beacon technology (NASBA-beacon) was compared to standard NASBA with postamplification hybridization using electrochemiluminescently labeled probes (NASBA-ECL) for detection of enteroviruses (EV) in 133 cerebrospinal fluid and 27 stool samples. NASBA-ECL and NASBA-beacon were similar in sensitivity, detecting 55 (100%) and 52 (94.5%) ...

Experimental evolution methods can be used to address and illuminate issues central to the understanding of evolutionary theory. One of the most powerful of these methods involves the in vitro evolution of nucleic acid enzymes, taking advantage of the direct relationship between the genotype of a nucleic acid sequence and ...

At pH 9.75, the resonance light scattering (RLS) intensity of OA-Eu3+ system is greatly enhanced by nucleic acid. Based on this phenomenon, a new quantitative method for nucleic acid in aqueous solution has been developed. Under the optimum condition, the enhanced RLS is proportional to the concentration of nucleic acid ...

BACKGROUND: Phytoliths (microscopic opal silica particles produced in and between the cells of many plants) are a very resilient, often-preserved type of microfossil and today, phytolith analysis is widely used in palaeoenvironmental studies, botany, geology and archaeology. To date there has been little standardization in the way phytoliths are described ...

Aptamers are unique nucleic acids with regulatory potentials that differ markedly from those of proteins. A significant feature of aptamers not possessed by proteins is their ability to participate in at least two different types of three-dimensional structure: a single-stranded folded structure that makes multiple contacts with the aptamer target ...

Stable isotope probing (SIP) is a technique that is used to identify the microorganisms in environmental samples that use a particular growth substrate. The method relies on the incorporation of a substrate that is highly enriched in a stable isotope, such as (13)C, and the identification of active microorganisms by ...

Synthetic carbohydrates and glycoconjugates are used to study their roles in biological important processes such as inflammation, cell-cell recognition, immunological response, metastasis, and fertilization. The development of an automated oligosaccharide synthesizer greatly accelerates the assembly of complex, naturally occurring carbohydrates as well as chemically modified oligosaccharide structures and promises to ...

The adsorption of ethene, propene, 1-butene, trans-2-butene, and isobutene on phosphotungstic acid has been characterized by density functional theory (DFT) calculations and microcalorimetric experiments. The DFT-calculated chemisorption energies to form the corresponding alkoxides for ethene, propene, 1-butene, trans-2-butene, and isobutene were -86.8, -90.3, -102.6, -79.9, and -91.4 kJ mol(-1), respectively ...

This review outlines the synthesis of covalent conjugates of oligonucleotides and their analogues that are obtained by reactions of carbonyl compounds with various nucleophiles such as primary amines, N-alkoxyamines, hydrazines, and hydrazides. The products linked by imino, oxime, hydrazone, or thiazolidine groups are shown to be useful intermediates for a ...

Five two-photon excitable dipyrrylmetheneboron difluoride labels (dipyrrylmethene-BF(2) labels) with fluorescence emission maximum between 530 and 590 nm, and a frequently used rhodamine label, TAMRA, were conjugated to aminomodified oligonucleotides. The performance of the labeled oligonucleotides was studied in a separation-free nucleic acid hybridization assay using ArcDia TPX bioaffinity assay technology. ...

BACKGROUND: The protocols of WHO network laboratories facilitated development of rapid diagnosis for SARS coronavirus (CoV) using reverse transcription (RT)-PCR assays. However, several reports have shown that conventional and real-time PCR assays were very specific for SARS CoV but lack sensitivity depending on the assay, specimen, and time course of ...

Since organelle preparations often contain more than one organelle type (e.g., acidic organelles and mitochondria), techniques that measure the properties of a given organelle type while avoiding biases caused by ancillary subcellular compartments are highly desirable. We report here the use of capillary electrophoresis (CE) with laser-induced fluorescence (LIF) dual-channel ...

The Workshop on "New Trends in Nucleic Acids Based Biosensors" was held at the University of Florence (Italy), from 25th to 28th October 2003. The workshop was funded by the European Science Foundation (ESF) within the programme "Functional Genomics" (Programme Area: DNA arrays and chips). This report describes the main ...

The genus Brevibacterium has long been difficult for taxonomists to classify due to its close morphological similarity to other genera. Since it was proposed in 1953, the genus has often been redefined. The genus is best known for its important role in the ripening of certain cheeses (B. linens) and ...

Nucleic acid amplification techniques are used for signal generation in antibody-based immunoassays, thereby dramatically enhancing the sensitivity of conventional immunoassays. Methodological aspects, as well as applications of this novel approach, are summarized in this review, with an emphasis on immuno-polymerase chain reaction (IPCR). IPCR is based on chimeric conjugates of ...

This review is focused on the capillary electrophoresis-mass spectrometric (CE-MS) analysis of nucleic acid constituents in the broadest sense, going from nucleotides and adducted nucleotides over nucleoside analogues to oligonucleotides. These nucleic acid constituents play an important role in a variety of biochemical processes. Hence, their isolation, identification, and quantification ...

Thiolated nucleic acids 1 or 2 are immobilized on Au-coated cantilevers and hybridized with the complementary nucleic acids 1a or 2a associated with magnetic particles. The duplexes 1/1a or 2/2a include specific sequences for the scission by Apa I or Mse I, respectively. The cantilevers positioned in a flow cell ...

OBJECTIVE: To develop a new sampling medium for detecting of bioaerosols. METHODS: The sampling media were tested by using Escherichia coli, Staphylococcus aureus and Serratia marcescens under static and active conditions, preliminary applications were performed using AGI-10 and high volume sampler. RESULTS: The average recovery rates were raised to 24.7%, ...

Substantial effort is currently being devoted to engineering allosteric nucleic acids, aptamers and ribozymes for various applications in cellular and molecular biology, biotechnology and diagnostics. These molecular switches alter their different functional activities in response to specific binding molecules, including proteins, nucleic acids and small organic compounds. The interacting molecules ...