Abstract:
A sensor chip that includes: a fluorescence quenching surface; a nucleic acid probe that contains first and second ends with the first end bound to the fluorescence quenching surface, a first region, and a second region complementary to the first region, the nucleic acid probe having, under appropriate conditions, either a hairpin conformation with the first and second regions hybridized together or a non-haipin conformation; and a first fluorophore bound to the second end of the first nucleic acid molecule. When the first nucleic acid molecule is in the hairpin conformation, the fluorescence quenching surface substantially quenches fluorescent emissions by the first fluorophore; and when the first nucleic acid molecule is in the non-harpin conformation, fluorescent emissions by the fluorophore are substantially free of quenching by the fluorescence quenching surface. Various nucleic acid probes, methods of making the sensor chip, biological sensor devices that contain the sensor chip, and their mehtods of use are also disclosed.
Abstract:
The present invention demonstrates a method for performing quantitative or qualitative analysis on a crude biological or environmental sample utilizing quantitative real-time PCR (QPCR).
Abstract:
Method for detecting and identifying unknown bioagents, including bacteria, viruses and the like, by a combination of nucleic acid amplification and molecular weight determination using primers which hybridize to conserved sequence regions of nucleic acids derived from a bioagent and which bracket variable sequence regions that uniquely identify the bioagent. The result is a base composition signature (BCS) which is then matched against a database of base composition signatures, by which the bioagent is identified.
Abstract:
The invention concerns a method of culturing, propagating and replicating in vitro viruses of the Togaviridae and Flaviviridae families which consists in: providing at least a fraction of LVP's obtained from serum or plasma of a patient infected with at least a virus of the Togaviridae and Flaviviridae families; contacting said fraction, for a predetermined time interval in an appropriate culture medium, with permissive cells having an endocytosis path relayed by at least one receptor of the lipoproteins and modulated inter alia by an activating agent selected among an unsaturated fatty acid or an unsaturated fatty acid derivative comprising 16 to 20 carbon atoms or their mixture. The invention also concerns the uses of viral particles and polypeptides obtained by said method.
Abstract:
The present invention relates to DNAzymes (also known as deoxyribozymes, DNA enzymes, catalytic DNA, or DZ), which are conjugated to nanoparticles (NP) to facilitate the detection of nucleic acids. One aspect of the invention relates to compounds comprising DNAzymes conjugated to nanoparticles (DZ-NP), such as metallic or gold nanoparticles, and methods for their synthesis. Another aspect of the invention relates to methods of using the conjugated compounds to detect nucleic acids, such as genomic material or transcripts of infectious agents, such as viruses, exemplified by applications demonstrating visual detection of Flavivirus RNA molecules, such as dengue virus, or Alphavirus RNA molecules, such as chikungunya virus, in short time periods, using compositions comprising stable components.
Abstract:
The present invention provides kits and assay methods for the early detection of pathogens, precise identification of the etiologic agent, and improved disease surveillance. More specifically, the present invention discloses an immunoassay leading to the rapid and simultaneous detection of antibodies to a wide range of infectious pathogens in biological fluids of infected patients. This immunoassay involves the covalent and oriented coupling of fusion proteins comprising an AGT enzyme and a viral antigen on an identifiable solid support (e.g. fluorescent microspheres), said support being previously coated with an AGT substrate. This coupling is mediated by the irreversible reaction of the AGT enzyme on its substrate. The thus obtained antigen-coupled microspheres show enhanced capture of specific antibodies as compared to antigen-coupled microspheres produced by standard amine coupling procedures. The methods of the invention possess the ability to multiplex, minimize the amount of biological sample, and have enhanced sensitivity and specificity toward target antibodies as compared with classical ELISA or Radio-Immunoprecipitation assays.
Abstract:
The present invention relates to a novel enhancer of protein production in host cells. It discloses a vector for expressing recombinant proteins in these cells, comprising a nucleotide sequence encoding a) a secretion peptidic signal, b) a 6-methylguanine-DNA-methyltransferase enzyme (MGMT, EC 2.1.1.63), a mutant or a catalytic domain thereof,and c) a recombinant protein. Said MGMT enzyme is preferably the so-called SNAP protein.
Abstract:
The present invention relates to a new method to determine the presence of antibodies to a pathogen in a serological sample using a new detection reagent which comprises at least two and preferably at least four copies of an antigen from the pathogen and a detectable marker. The present invention also relates to a new detection reagent which consists of at least two and preferably at least four antigenic peptides in a complex with a detectable marker via interacting multimerization domains upon both the antigenic peptides and detectable marker.
Abstract:
Methods for detecting polynucleotides, especially the DNA replicated from samples obtained from subjects infected with pathogenic viruses such as human immunodefiency virus, by detecting electromagnetic signals ("EMS") emitted by such polynucleotides, and methods for improving the sensitivity of the polymerase chain reaction ("PCR").