Background SELEX is a well established in vitro selection tool to analyze the structure of ligand-binding nucleic acid sequences called aptamers. Genomic SELEX transforms SELEX into a tool to discover novel, genomically encoded RNA or DNA sequences binding a ligand of interest, called genomic aptamers. Concerns have been raised regarding requirements imposed on RNA sequences undergoing SELEX selection. Methodology/Principal Findings To evaluate SELEX and assess the extent of these effects, we designed and performed a Neutral SELEX experiment omitting the selection step, such that the sequences are under the sole selective pressure of SELEXs amplification steps. Using high-throughput sequencing, we obtained thousands of full-length sequences from the initial genomic library and the pools after each of the 10 rounds of Neutral SELEX. We compared these to sequences obtained from a Genomic SELEX experiment deriving from the same initial library, but screening for RNAs binding with high affinity to the E.
Systematic evolution of ligands by exponential enrichment (SELEX), also referred to as in vitro selection or in vitro evolution, is a combinatorial chemistry technique in molecular biology for producing oligonucleotides of either single-stranded DNA or RNA that specifically bind to a target ligand or ligands. Although SELEX has emerged as the most commonly used name for the procedure, some researchers have referred to it as SAAB (selected and amplified binding site) and CASTing (cyclic amplification and selection of targets) SELEX was first introduced in 1990. In 2015 a special issue was published in the Journal of Molecular Evolution in the honor of quarter century of the SELEX discovery. The process begins with the synthesis of a very large oligonucleotide library consisting of randomly generated sequences of fixed length flanked by constant 5 and 3 ends that serve as primers. For a randomly generated region of length n, the number of possible sequences in the library is 4n (n positions with ...
Aptamer selection protocols, named cell-SELEX, have been developed to target trans-membrane proteins using whole living cells as target. This technique presents several advantages. (1) It does not...
Dynamical systems are often used to model biochemical and biological processes. In Seo et al. (2010, 2014) we studied two mathematical models of the iterative biochemical procedure known as SELEX (Systematic Evolution of Ligands by EXponential Enrichment): multiple target SELEX and alternate SELEX. It is the purpose of this paper to revisit the mathematics of these processes in the language of dynamical systems on compact manifolds but for a dynamical system on a manifold with compact closure. From the experimentalists point of view, multiple target SELEX provides a way of obtaining the best binding ligands to a pool of several fixed targets, whereas alternate SELEX provides a way to specify which of the best binding ligands also bind best to a specified subtarget. Because these procedures are iterative, it is natural to investigate them in the context of the theory of discrete dynamical systems. Although the iterative schemes are nonautonomous, they have the same limiting properties as two closely
Some bioterrorism agents cause disease at very low infective doses and their presence can be masked by the environment. Therefore, ultrasensitive detection is required for homeland defense applications. In this Phase I research project, Operational Technologies Corporation (OpTech) proposes to couple DNA aptamers made by the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) process to commercially available fluorescent nanoparticles (NPs, composed of chelated europium in polystyrene). OpTech will demonstrate aptamer-NP-mediated detection of a bacterial, viral, and toxin simulant at low levels. Fluorescent NPs are nanometer-sized plastic and metallic ¿beads¿ that endow superior sensitivity in clinical assays (up to zeptomolar [10-21] detection limits). OpTech also will couple the DNA aptamers to magnetic microbeads and demonstrate magnetic separation and purification of the bioterrorism agent simulants from natural water samples in conjunction with aptamer-fluorescent NP ...
Aptamers are a class of therapeutic oligonucleotides that form specific three-dimensional structures that are dictated by their sequences. They are typically generated by an iterative screening process of complex nucleic acid libraries employing a process termed Systemic Evolution of Ligands by Exponential Enrichment (SELEX). SELEX has traditionally been performed using purified proteins, and cell surface receptors may be challenging to purify in their properly folded and modified conformations. Therefore, relatively few aptamers have been generated that bind cell surface receptors. However, improvements in recombinant fusion protein technology have increased the availability of receptor extracellular domains as purified protein targets, and the development of cell-based selection techniques has allowed selection against surface proteins in their native configuration on the cell surface. With cell-based selection, a specific protein target is not always chosen, but selection is performed against a
1. Protein Binding Microarray (PBM). PBMs use microarrays with double-stranded DNA probes to measure the fluorescence of alphaGST-tagged proteins bound to their sequence-specific binding sites on the probes. There are quite a few different PBM designs - with the UPBM, ME, and HK being the most popular. All three of these designs have roughly 44K DNA probe sequences that are engineered using deBruijn sequences to cover (nearly) all overlapping 10-mers at least once.. Advantages: Fast, relatively inexpensive, and provides real-valued measurements of binding.. Disadvantages (2015): Most array designs only cover all 10-mers, making it difficult to model binding sites larger than 10 base pairs. Contains a strong artifact of preferential binding at binding positions near the free-ends of the probes.. 2. SELEX-seq/HT-SELEX. The SELEX-seq (also called HT-SELEX) method combines classical protein-DNA SELEX (Systematic Evolution of Ligands by EXponential enrichment) assays with massively parallel ...
Susan Patrick is the author of this article in the Journal of Visualized Experiments: Primer-Free Aptamer Selection Using A Random DNA Library
MA0073 22.2782723704014 RREB1 ZN-FINGER, C2H2 ; acc "Q92766" ; medline "8816445" ; seqdb "SWISSPROT" ; species "Homo sapiens" ; sysgroup "vertebrate" ; total_ic "22.2800" ; type "SELEX" MA0075 9.06306510239135 Prrx2 HOMEO ; acc "Q06348" ; medline "7901837" ; seqdb "SWISSPROT" ; species "Mus musculus" ; sysgroup "vertebrate" ; total_ic "9.0620" ; type "SELEX" MA0070 14.6408952002356 Pbx HOMEO ; acc "P40424" ; medline "7910944" ; seqdb "SWISSPROT" ; species "Homo sapiens" ; sysgroup "vertebrate" ; total_ic "14.6440" ; type "SELEX" MA0079 9.7185757452318 SP1 ZN-FINGER, C2H2 ; acc "P08047" ; medline "2192357" ; seqdb "SWISSPROT" ; species "Homo sapiens" ; sysgroup "vertebrate" ; total_ic "9.7160" ; type "SELEX" MA0077 9.07881462267179 SOX9 HMG ; acc "P48436" ; medline "9973626" ; seqdb "SWISSPROT" ; species "Homo sapiens" ; sysgroup "vertebrate" ; total_ic "9.0810" ; type "SELEX" MA0078 10.5018372361999 Sox17 HMG ; acc "Q61473" ; medline "8636240" ; seqdb "SWISSPROT" ; species "Mus musculus" ; ...
Cruz-Toledo, J.; McKeague, M.; Zhang, X.; Giamberardino, A.; McConnell, E.; Francis, T.; DeRosa, M.C.; Dumontier, M. Aptamer Base: A collaborative knowledge base to describe aptamers and SELEX experiments. Database: Journal of Biological Databases and Curation. 2012 ...
Nucleic acid aptamers are short single-stranded DNA or RNA oligonucleotides that can bind to their targets with very high affinity and specificity, and are generally selected by a process referred to as systematic evolution of ligands by exponential enrichment. Conventional antibody-based therapeutic and diagnostic approach currently employed against biotoxins pose major limitations such as the requirement of a live animal for the in vivo enrichment of the antibody species, decreased stability, high production cost, and side effects. Aptamer technology is a viable alternative that can be used to combat these problems. Fully sequestered in vitro, aptamers eliminate the need for a living host. Furthermore, one of the key advantages of using aptamers instead of antibodies is that they can be selected against very weakly immunogenic and cytotoxic substances. In this review, we focus on nucleic acid aptamers developed against various biotoxins of plant, microorganism, or animal origin and show how ...
Human Immunodeficiency Virus (HIV) reverse transcriptase (RT) is the most common molecular target of current HIV treatments. Oligonucleotide aptamers bind and inhibit the RNA- and DNA-dependent polymerization activities of HIV RT. Libraries consisting of aptamers including 32, 70 or 80 nucleotide variable regions were previously screened by Systematic Evolution of Ligands by Exponential Enrichment (SELEX) against RT. Roughly half of the resulting aptamers were represented by pseudoknots with well defined signature sequences (the Family I), but also additional pseudoknots with little sequence convergence (Family II), and non-pseudoknot aptamers (Family III). Nucleic acid aptamers bind RT in the primer/template binding site. Aptamers are generally non-toxic and non-immunogenic molecules making them enticing drug prospects. Many aptamers inhibit DNA dependent DNA polymerization by RT from several phenotypically different recombinant viruses, but inhibition depends on a single amino acid mutation at ...
The demand has increased for sophisticated molecular tools with improved detection limits. Such molecules should be simple in structure, yet stable enough for clinical applications. Nucleic acid aptamers (NAAs) represent a class of molecules able to meet this demand. In particular, aptamers, a class of small nucleic acid ligands that are composed of single-stranded modified/unmodified RNA/DNA molecules, can be evolved from a complex library using Systematic Evolution of Ligands by EXponential enrichment (SELEX) against almost any molecule. Since its introduction in 1990, in stages, SELEX technology has itself undergone several modifications, improving selection and broadening the repertoire of targets. This review summarizes these milestones that have pushed the field forward, allowing researchers to generate aptamers that can potentially be applied as therapeutic and diagnostic agents.
After three decades, the human immunodeficiency virus type 1 (HIV-1) remains a global pandemic. It has been difficult to develop therapeutic agents and vaccines against HIV due partly to the virus s ability to mutate rapidly. As a result, there is a constant need to develop new therapeutic agents that target HIV-1. This research seeks to develop an RNA aptamer that would bind tightly to the Pre-Hairpin Intermediate state of the HIV-1 envelope glycoprotein gp41 to inhibit viral fusion. The project targets the envelope glycoprotein of HIV-1, gp41, with nucleic acid aptamers. Aptamers are selected from random pools (libraries) by an in vitro selection called Systematic Evolution of Ligands by Exponential Enrichment (SELEX). The aptamers go through rounds of selection, where the weak binders will be washed off in each round. Once these aptamers are developed, they will be tested for their ability to prevent viral membrane fusion, and their potential use in HIV therapeutics. ...
Aptamer Solutions Ltd is a York based Biotechnology Company specialising in the custom selection of high-affinity and highly specific nucleic acid aptamers for use in the life sciences sector. Our proprietary automated high-throughput aptamer selection processes allow us to offer a flexible and competitive pricing structure for the development of RNA and DNA aptamers. In addition, we are about to launch a new complementary technology in the area of biomarker discovery.. Our proprietary aptamer based biomarker discovery platform and proprietary combinatorial libraries contain up to and over 1018 different molecules, this diversity and bespoke library design is fundamental to the success of the screening process. This technology enables us to greatly speed up the identification of novel biomarkers as well as diagnostics and/or therapeutic candidate molecules. This technology builds on one of the most powerful uses of aptamer technology, which is the ability for aptamers to be isolated against ...
Aptamers are single-stranded oligonucleotides isolated via in vitro systematic evolution of ligands by exponential enrichment (SELEX),1,2 which can specifically bind to a wide range of targets including proteins, small molecules and metal ions.3 Aptamers offer several advantages as recognition elements for biosensor applications relative to antibodies. First, aptamers can be chemically synthesized with high reproducibility at relatively low cost.4,5 Second, the high chemical stability of DNA aptamers means that they can be used under harsher conditions and stored with a longer shelf life.6 Finally, it is possible to generate unstructured aptamers that form specific secondary structures such as three-way junctions7,8 or tertiary folds such as G-quadruplex structures9,10 upon target binding. Such target-induced conformational changes can be readily exploited for specific target detection in a variety of applications, including medical diagnostics, environmental monitoring and drug screening.11-13 ...
ELRIG are busily preparing for the 8th Annual Drug Discovery conference which will be held at Manchester Convention Centre on 2nd & 3rd September 2014. The programme contain presentations from leading scientists across Europe and beyond, covering exciting advances in basic and translational aspects of drug discovery and brings together Academia, Biotech, Vendors and Pharma into a single community.. Aptamer Group are delighted to be invited back to the Innovation Zone (stand IZ12) for the second year running, where we will be exhibiting our new and exciting technologies. We have over 20 years combined expertise in the development of nucleic acid aptamers to peptides, proteins, cells, tissue samples, micro-organisms and small molecules.. Dr David Bunka, CTO, world leading high-throughput aptamer selection expert will be addressing the Target Validation audience on 3 September at 12.00 in Charter 1. Dr Bunka will be discussing how our technology enables us to greatly speed up the identification of ...
An L-ribonucleic acid aptamer (L-RNA aptamer, trade name Spiegelmer - from German Spiegel "mirror" - by Noxxon Pharma) is an RNA-like molecule built from L-ribose units. It is an artificial oligonucleotide named for being a mirror image of natural oligonucleotides. L-RNA aptamers are a form of aptamers. Due to their L-nucleotides, they are highly resistant to degradation by nucleases. Spiegelmers are considered potential drugs and are currently being tested in clinical trials. Spiegelmers, built using L-ribose, are the enantiomers of natural oligonucleotides, which are made with D-ribose. Nucleic acid aptamers, including L-RNA aptamers, contain adenosine monophosphate, guanosine monophosphate, cytidine monophosphate, uridine monophosphate, a phosphate group, a nucleobase and a ribose sugar. Like other aptamers, L-RNA aptamers are able to bind molecules such as peptides, proteins, and substances of low molecular weight. The affinity of L-RNA aptamers to their target molecules often lies in the ...
Apple Stem Pitting Virus of PSAH PearIsolate, DNA Aptamer, Biotinylated DNA Aptamers AD-107-B Apple Stem Pitting Virus of PSAH PearIsolate, DNA Aptamer, Biotinylated DNA Aptamers AD-107-B
Apple Stem Pitting Virus of PSAH PearIsolate, DNA Aptamer, Biotinylated DNA Aptamers AD-107-B Apple Stem Pitting Virus of PSAH PearIsolate, DNA Aptamer, Biotinylated DNA Aptamers AD-107-B
Multitasking by Multivalent Circular DNA Aptamers | Daniel A. Di Giusto; Sarah M. Knox; Yuching Lai; Gregory D. Tyrelle; May T. Aung; Garry C. King | download | BookSC. Download books for free. Find books
and / or polyclonal antibodies specific to a particular target for capture and / or quantitative detection. Most ELISAs employ a 96-well plate-based format. ELISAs are currently used in a wide range of industries, with wide-spread application for the detection of protein biomarkers in research, diagnostics and therapeutics. While antibody-based immunoassays have proven to be very sensitive and specific, there are some limitations which can be overcome with the ELASA, or Enzyme-Linked Aptamer Sorbent Assay. Unlike antibodies, aptamers can be selected for specific binding to poorly immunogenic and toxic compounds. Aptamers can also distinguish between highly conserved molecules. Chemical aptamer synthesis enables rapid, low-cost production of new batches with low lot-to-lot variability. As with traditional ELISAs, ELASAs can be direct, indirect, and sandwich assays. Several sandwich ELASA assays have been developed at Base Pair Biotechnologies. Biotinylated capture aptamers are typically bound to ...
Identifying targets that are exposed on the plasma membrane of tumor cells, but expressed internally in normal cells, is a fundamental issue for improving the specificity and efficacy of anticancer therpeutics. Using blind cell SELEX (Systemic Evolution of Ligands by EXponetial enrichment) which is untargeted SELEX, we have identified an aptamer, P15, which specifically bound to the human pancreatic adenocarcinoma cells. To identify the aptamer binding plasma membrane protein, liquid chromatography tandem mass spectrometry (LC-MS/MS) was used. The results of this unbiased proteomic mass spectrometry approach identified the target of P15 as the intermediate filament vimentin, biomarker of epithelial mesenchymal transition (EMT), which is an intracellular protein but is specifically expressed on the plasma membrane of cancer cells. As EMT plays a pivotal role to transit cancer cells to invasive cells, tumor cell metastasis assays were performed in vitro. P15 treated pancreatic cancer cells showed ...
Infectious diseases are a subject of public health safety. In case of events such as bioterrorism or food samples tainted with a disease causing bacteria or virus the standard traditional methods of detection of viral or bacterial detection are too slow. We have developed molecular probes known as ?aptamers? to detect infection with high specificity and sensitivity. Aptamer, a word derived from Latin ?aptus? meaning ?to fit?; are molecular probes which are generated using nucleic acids which recognize and bind their target with a very high affinity and specificity. Aptamers are evolved in vitro in a test tube for its target. Aptamers are generated using a screening process known an SELEX, which stands for Systematic Evolution of Ligands by Exponential Enrichment. A library of 10 14 to 10 16 unique sequences is synthesized. These sequences are fractionated based on interactions with the target for which the aptamer is generated. The weaker binding sequences are weeded out after each successive ...
Aptamers are typically selected from libraries of random DNA (or RNA) sequences through systematic evolution of ligands by exponential enrichment (SELEX), which involves several rounds of alternating steps of partitioning of candidate oligonucleotides and their PCR amplification. Here we describe a protocol for non-SELEX selection of aptamers - a process that involves repetitive steps of partitioning with no amplification between them. Non-equilibrium capillary electrophoresis of equilibrium mixtures (NECEEM), which is a highly efficient affinity method, is used for partitioning. NECEEM also facilitates monitoring of bulk affinity of enriched libraries at every step of partitioning and screening of individual clones for their affinity to the target. NECEEM allows all clones to be screened prior to sequencing, so that only clones with suitable binding parameters are sequenced. The entire protocol can be completed in 1 wk, whereas conventional SELEX protocols take several weeks even in a specialized
Inhibitors of β-lactamases are important to the treatment of infectious diseases when used in conjunction with a β-lactam antibiotic. Current inhibitors of β-lactamase such as clavulanic acid, sulbactam, and tazobactam perform efficiently overall but due to developing bacterial resistances to these inhibitors, new inhibitors need to be discovered. SELEX procedures were used to isolate ssDNA aptamers capable of binding to the enzyme active site and consequently inhibit the action of β-lactamase I from Bacillus cereus 569/H/9. A 22 base ssDNA aptamer was discovered to have an inhibition pattern consistent with reversible competitive inhibition. These results prompted further study of a hairpin loop of 10 bases and a linear 11 base ssDNA aptamer which were truncated forms of the original 22 base aptamer. The 11 base aptamer failed to show any inhibition against β-lactamase I, whereas the 10 base aptamer showed competitive reversible inhibition ...
Cell-derived nanosized vesicles or exosomes are expected to become delivery carriers for functional RNAs, such as small interfering RNA (siRNA). A method to efficiently load functional RNAs into exosomes is required for the development of exosome-based delivery carriers of functional RNAs. However, there is no method to find exosome-tropic exogenous RNA sequences. In this study, we used a systematic evolution of ligands by exponential enrichment (SELEX) method to screen exosome-tropic RNAs that can be used to load functional RNAs into exosomes by conjugation. Pooled single stranded 80-base RNAs, each of which contains a randomized 40-base sequence, were transfected into B16-BL6 murine melanoma cells and exosomes were collected from the cells. RNAs extracted from the exosomes were subjected to next round of SELEX. Cloning and sequencing of RNAs in SELEX-screened RNA pools showed that 29 of 56 clones had a typical RNA sequence. The sequence found by SELEX was enriched in exosomes after transfection to B16
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Shigdar, Sarah, Lv, Li, Wang, Lifen and Duan, Wei 2016, Application of aptamers in histopathology. In Mayer, Gunter (ed), Nucleic acid aptamers : selection, characterization and application, Humana Press, New York, N.Y., pp.191-196, doi: 10.1007/978-1-4939-3197-2_16. ...
DNA and RNA aptamers interact with their target proteins with high selectivity, specificity and affinity. The SELEX method consists of iterative cycles of in vitro screening of a combinatorial oligonucleotide library containing to 1016 different molecules and possible secondary and tertiary structures for target binding followed by PCR amplification of selected sequences. Aptamer ligands can be developed against almost any target protein. Due to the wide spectrum of applications, these novel molecules are used in numerous pharmacological, clinical and industrial processes. In the beginning, RNA and DNA aptamers were identified which bind to proteins that naturally interact with nucleic acids or small molecules such as ATP. In the following years, the use of the SELEX technique was extended in order to isolate oligonucleotide ligands for a wide range of proteins of importance for therapy and diagnostics, such as growth factors (3), cell surface antigens, entire cells and even whole organisms. ...
Background: RNA aptamers are small RNA molecules that bind antigens like antibodies and are currently being explored as alternatives to antibodies for diagnosis and therapy. A potential merit of aptamers is that they can be generated against native cellular antigens, such as those with unique post-translational modifications or receptor-ligand complexes, for which antibody generation can be difficult. Here, we report the use of a cell-based systematic enrichment approach (SELEX) to develop a novel Treg-binding RNA aptamer specific to IL2Rα-IL2 receptor-ligand complex.. Methods and Results:. A. Generation of Treg-binding aptamers:. We designed a cell-based SELEX strategy to generate RNA aptamers specific to human T regulatory (Treg) cells. The starting library consisted of random RNA aptamers with a structural diversity of ~1012. Aptamers against common T cell antigens were pre-cleared using CD4+CD25- Teff cells. Treg-binding aptamers were then positively selected using CD4+CD25+ Tregs from the ...
Video articles in JoVE about mercuric chloride include Characterization of Glycoproteins with the Immunoglobulin Fold by X-Ray Crystallography and Biophysical Techniques, Chick Heart Invasion Assay for Testing the Invasiveness of Cancer Cells and the Activity of Potentially Anti-invasive Compounds, Production of Germ-Free Fast-Growing Broilers from a Commercial Line for Microbiota Studies, Assessment of Hippocampal Dendritic Complexity in Aged Mice Using the Golgi-Cox Method.
The Systematic Evolution of Ligands by EXponential enrichment (SELEX) process has allowed the discovery of aptamers with the ability to bind target molecules with high affinity and specificity. This opens up avenues to develop easy, selective and cost-effective methods to monitor aptamer-target interactions. Conventional optical assays involve the functionalization of the termini of an oligonucleotide with a fluorophore and a quencher for detecting analytes. In this work, i utilized nucleic acid staining reagents as chromophores to develop a signaling strategy that avoids synthetic modification of aptamers. Three different aptamers (thrombin-, theophylline-, and ATP-binding aptamers) that span a range of sizes, secondary structures and affinities were employed for this work. I monitored the formation of the fluorescent complex by nucleic acid and chromophore in the presence and absence of a cognate target. My study reveals that the chromophores SYBR Green I and thiazole orange (TO) can be used across
Aptamers, synthetic oligonucleotide‐based molecular recognition probes, have found use in a wide array of biosensing technologies based on their tight and highly selective binding to a variety of molecular targets
LC Sciences provides unique aptamer microarray services using a novel µParaflo technology, a list of aptamer sequences, and sequence design software. The
The adenosine aptamer was split into two halves and linked to a fluid liposome surface; addition of adenosine resulted in aptamer assembly, which did not occur if the split aptamer was attached to silica nanoparticles, demonstrating the feasibility of using aptamer probes to study diffusion within lipid membranes ...
antibody-antibodies.com is the marketplace for research antibodies. Find the right antibody for your research needs. Enzymatic conjugation of multiple proteins on a DNA aptamer in a tail-specific manner.
Aptamers are oligonucleotides that bind ligands-sometimes strongly and sometimes very specifically. They are, or will be, the basis of therapeutics, assays, and sensors. We consider how these molecules are designed and selected, and to what extent computational methods have helped or might help. ...
Principal Investigator:UNEYAMA Kenji, Project Period (FY):2001 - 2003, Research Category:Grant-in-Aid for Scientific Research (B), Section:展開研究, Research Field:Synthetic chemistry
We report an aptamer functionalized stimuli responsive surface that can controllably switch between binding and releasing its specific ligand under application of electrical stimuli. The high affinity of the aptamer for thrombin makes the surface undergo specific binding while electrostatic field induced act
Human Neutrophil Elastase (DNA I) , DNA Aptamer, Biotinylated DNA Aptamers AD-155-B Human Neutrophil Elastase (DNA I) , DNA Aptamer, Biotinylated DNA Aptamers AD-155-B
70846 Oilseed contains sterols and related compounds with economic potential. The extraction and analysis of these compounds would be aided by the availability of highly selective aptamers with high affinities for their particular sterol ligands. This project will develop aptamers for use in microarrays to analyze and extract sterol contents of oil and other biological extracts. Bacterial expression vectors will be prepared from which the aptamers can be expressed in large quantities. In Phase I, one or more DNA aptamers for sitosterol will be selected. The aptamers will be evaluated for their specificity and affinity for sitosterol and related compounds. A bacterial expression vector will be developed from which aptamers can be prepared. Commercial Applications and Other Benefits as described by the awardee: Commercial applications include (1) the use of aptamers in the analysis and extraction of sitosterol and related compounds, and (2) a general method for economically mass-producing DNA ...
DNA aptamers were developed against murine norovirus (MNV) using SELEX (Systematic Evolution of Ligands by EXponential enrichment). Nine rounds of SELEX led to the discovery of AG3, a promising aptamer with very high affinity for MNV as well as for lab-synthesized capsids of a common human norovirus (HuNoV) outbreak strain (GII.3). Using fluorescence anisotropy, AG3 was found to bind with MNV with affinity in the low picomolar range. The aptamer could cross-react with HuNoV though it was selected against MNV. As compared to a non-specific DNA control sequence, the norovirus-binding affinity of AG3 was about a million-fold higher. In further tests, the aptamer also showed nearly a million-fold higher affinity for the noroviruses than for the feline calicivirus (FCV), a virus similar in size and structure to noroviruses. AG3 was incorporated into a simple electrochemical sensor using a gold nanoparticle-modified screen-printed carbon electrode (GNPs-SPCE). The aptasensor could detect MNV with a ...
Molecular and Functional Characterization of ssDNA Aptamers that Specifically Bind Leishmania infantum PABP. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
The Society for Laboratory Automation and Screening (SLAS) announces the winner of the $10,000 SLAS Innovation Award presented at LabAutomation2011. Kamlesh Patel, Senior Scientist, Sandia National Laboratories, was honored for his outstanding podium presentation, Preparation of Nucleic Acid Libraries for Ultra High Throughput Sequencing with a Digital Microfluidic Hub.
Disclosed are single-stranded DNA molecules which bind adenosine or an adenosine-5-phosphate and methods for their production and isolation. Also disclosed are methods for producing and isolating related catalytic DNA molecules.
Although the vast majority of such ligand binding activities or enzymatic activities known are performed by proteins a secondary subset of these fall under the category of Functional nucleic acids (FNAs). FNAs are RNA, ssDNA, or XNA(nucleic acid analogues) that perform an activity such as binding or catalyzing a reaction. FNAs are grouped into three main categories Aptamers, Ribozymes, and Deoxyribozymes that are further classified into either natural or artificial depending on their origin. The exception being Deoxyribozymes as they have yet to be discovered in a living organism. Still, It was only in the 1980s that the 1st ribozyme was discovered that we started to study FNAs and have allowed for the discovery of new methods, such as the SELEX or In vitro selection process that we are expanding their potential both as tools for exploring biology and real world problem solving. Note to self: mention RNA World ...
RNA APTAMERS AGAINST BAFF-R AS CELL-TYPE SPECIFIC DELIVERY AGENTS AND METHODS FOR THEIR USE - In one embodiment, a B cell specific aptamer-siRNA chimera is provided. The B cell specific aptamer-siRNa chimera may include an RNA aptamer that binds BAFF-R and an siRNA molecule conjugated to the RNA aptamer via a nucleotide linker. In another embodiment, a B cell specific RNA aptamer is provided. The RNA aptamer may be a molecule that binds to BAFF-R that has the sequence SEQ ID NO:37, SEQ ID NO:38 or SEQ ID NO:39. In some embodiments, the RNA aptamer is conjugated, via a nucleotide linker, to an siRNA molecule that suppresses expression of one or more target oncogenes in one or more B cells. In one aspect, the one or more target oncogenes are selected from Bcl6, Bcl2, STAT3, Cyclin D1, Cyclin E2 and c-myc. In another embodiment, methods for treating a B cell malignancy in a cancer patient are provided. Such methods may include administering a therapeutically effective amount of a therapeutic ...
Data accumulated over the latest two decades have established that the serine protease urokinase-type plasminogen activator (uPA) is a potential therapeutic target in cancer. When designing inhibitors of the proteolytic activity of serine proteases, obtaining sufficient specificity is problematic, because the topology of the proteases active sites are highly similar. In an effort to generate highly specific uPA inhibitors with new inhibitory modalities, we isolated uPA-binding RNA aptamers by screening a library of 35 nucleotides long 2′-fluoro-pyrimidine RNA molecules using a version of human pro-uPA lacking the epidermal growth factor-like and kringle domains as bait. One pro-uPA-binding aptamer sequence, referred to as upanap-126, proved to be highly specific for human uPA. Upanap-126 delayed the proteolytic conversion of human pro-uPA to active uPA, but did not inhibit plasminogen activation catalyzed by two-chain uPA. The aptamer also inhibited the binding of pro-uPA to uPAR and the ...
Pivotal Scientific Ltd and Base Pair Biotechnologies Partner to Expand Access to Novel Aptamer Technologies to Global Markets. Oxfordshire, UK and Texas, US, June 3, 2013 - Pivotal Scientific Ltd, a consultancy company specialising in developing the international growth of biotech SMEs, and Base Pair Biotechnologies, a specialist developer of novel aptamer based technologies for research and diagnostics, are pleased to announce their collaboration to expand the reach of Base Pair Biotechnologies products and services.. A mainstay of bioscience research is the antibody. Yet standard antibody technologies can take months to produce an antibody against a new target; a long time in the fast paced and global arena of the biosciences. Base Pair Biotechnologies patented development process can turn around aptamers - short strands of DNA or RNA that specifically bind a target with equal specificity and affinity to antibodies - in weeks instead of months, getting researchers the reagents they need ...