135 results about "Fluorescent tag" patented technology

Novel nanowell microarrays are disclosed in optical contact with polymer waveguides wherein evanescent field associated with lightwaves propagated in the waveguide excite target substances in the nanowells either by a common waveguide or by individual waveguides. Fluid samples are conveyed to the nanowells by means of microfluidics. The presence of the target substances in fluid samples is detected by sensing fluorescent radiation generated by fluorescent tag bound to the target substances. The fluorescent tags generate fluorescent radiation as a result of their excitation by the evanescent field. One or more PMT detectors or a CCD detector are located at the side of the waveguide opposite to the nanowells. Fluorescent radiation is detected due to its coupling with the waveguide or its emission through the waveguide.

A micromechanical actuator for sorting hematopoietic stem cells for use in cancer therapies. The actuator operates by diverting cells into one of a number of possible pathways fabricated in the fabrication substrate of the micromechanical actuator, when fluorescence is detected emanating from the cells. The fluorescence results from irradiating the cells with laser light, which excites a fluorescent tag attached to the cell. The micromechanical actuator thereby sorts the cells individually, with an operation rate of 3.3 kHz, however with the massively parallel 1024-fold device described herein, a throughput of 3.3 million events/second is achievable.

A method of inhibiting light-induced degradation of nucleic acids includes irradiating a portion of the nucleic acids in the presence of a detection solution comprising a polyphenolic compound. A method of detecting a nucleic acid having a fluorescent tag includes irradiating at least a portion of the nucleic acid with light of a suitable wavelength to induce a fluorescence emission and detecting the fluorescence emission. Optionally, the polyphenolic compound is gallic acid, a lower alkyl ester thereof, or mixtures thereof. A kit includes one or more nucleotides, an enzyme capable of catalyzing incorporation of the nucleotides into a nucleic acid strand and a polyphenolic compound suitable for preparing a detection solution.

The invention relates to a microelectronic sensor device and a method for the investigation of biological target substances (20), for example oligonucleotides like DNA fragments. In one embodiment, the device comprises a reaction surface (RS) to which target specific reactants (10) are attached and which lies between a sample chamber (SC) and an array of selectively controllable heating elements (HE). The temperature profile in the sample chamber (SC) can be controlled as desired to provide for example conditions for a PCR and/or for a controlled melting of hybridizations. The reactant (10) and/or the target substance (20) comprises a label (12) with an observable property, like fluorescence, that changes if the target substance (20) is bound to the reactant (10), said property being detected by an array of sensor elements, for example photosensors (SE). The fluorescence of the label (12) may preferably be transferred by FRET to a different fluorescent label (22) or quenched if the target substance (20) is bound.

A method and apparatus for use in a flow through assay process is disclosed. The method is characterised by a “pre-incubation step” in which the sample which is to be analysed, (typically for the presence of a particular protein), and a detection analyte (typically an antibody bound to colloidal gold or a fluorescent tag) which is known to bind to the particular protein may bind together for a desired period of time. This pre incubation step occurs before the mixture of sample and detection analyte come into contact with a capture analyte bound to a membrane. The provision of the pre-incubation step has the effect of both improving the sensitivity of the assay and reducing the volume of sample required for an assay. An apparatus for carrying out the method is disclosed defining a pre-incubation chamber for receiving the sample and detection analyte having a base defined by a membrane and a second membrane to which a capture analyte is bound. In one version the pre-incubation chamber is supported above the second membrane in one position but can be pushed into contact with the membrane carrying the capture analyte thus permitting fluid transfer from the incubation chamber through the capture membrane. In another version the membrane at the base of the incubation chamber is hydrophobic and its underside contacts the capture membrane and when a wetting agent is applied to the contents of the pre-incubation chamber fluid transfer occurs.

A method and apparatus for use in a flow through assay process is disclosed. The method is characterised by a “pre-incubation step” in which the sample which is to be analysed (typically for the presence of a particular protein), and a detection analyte (typically one or more antibodies bound to colloidal gold or a fluorescent tag) which is known to bind to the particular protein may bind together for a desired period of time. This pre-incubation step occurs before the mixture of sample and detection analyte come into contact with a capture analyte bound to a membrane. The provision of the pre-incubation step has the effect of both improving the sensitivity of the assay and reducing the volume of sample required for an assay. An apparatus for carrying out the method is disclosed defining a pre-incubation chamber for receiving the sample and detection analyte having a base defined by a membrane and a second membrane to which a capture analyte is bound. In one version the pre-incubation chamber is supported above the second membrane in one position but can be pushed into contact with the membrane carrying the capture analyte thus permitting fluid transfer from the incubation chamber through the capture membrane. In another version the membrane at the base of the incubation chamber is hydrophobic and its underside contacts the capture membrane and when a wetting agent is applied to the contents of the pre-incubation chamber fluid transfer occurs.

Endotoxin, also known as lipopolysaccharides (LPS), is the major mediator of septic shock due to Gram-negative bacterial infection. Chemically synthesized S3 peptide, derived from Sushi3 domain of Factor C, which is the endotoxin-sensitive serine protease of the limulus coagulation cascade, binds and neutralizes LPS activity. Fluorescent tagged-S3 is shown to detect LPS-containing bacteria. For large-scale production of S3 and to mimic other pathogen-recognizing molecules, tandem multimers of the S3 gene were constructed and expressed in E. coli. Tetramer of S3 for example is shown to display an enhanced inhibitory effect on LPS-induced activities. An affinity matrix based on tetramer of S3 is also shown to be particularly efficient at removing LPS.

An apparatus (10) and method for use in a vertical flow-through assay process is characterised by applying pressure to a sample to force the sample through a reaction/capture membrane (12), to which one or more ligands are bound, at a controlled rate. Typically, the method includes a pre-incubation step in which the sample and a detection analyte typically an antibody bound to colloidal gold or a fluorescent tag bind together The pre-incubation step typically takes place in a chamber (26) spaced above the capture membrane (12). The base of the chamber is defined by a porous hydrophobic frit (34) typically formed from polyethylene. It is preferred that the chamber (26) is defined by the upper part of a cylinder (24) extending from a seal (30) compressing the reaction membrane (12) against an absorbent pad (28). The seal (30) has the effect of compressing tie reaction membrane and preventing wicking of the sample in the lateral direction outside of the circular seal. A piston (28) compresses air located in the chamber above atmospheric pressure to farce the sample to pass through the hydrophobic frit (34). Alternatively, a hydraulic actuator (60) may directly act on the sample to force the sample through the frit and reaction membrane at a predetermined rate.

This invention relates to a micromachined microfluidics diagnostic device that comprises one or multiple assaying channels each of which is comprised a sample port, a first valve, a reaction chamber, a second valve, a fluid ejector array, a third valve, a buffer chamber, a capture zone and a waste chamber. Each of these device components are interconnected through microfluidic channels. This invention further relates to the method of operating a micromachined microfluidic diagnostic device. The flow of fluid in the microchannels is regulated through micromachined valves. The reaction of sample analytes with fluorescent tags and detection antibodies in the reaction chamber are enhanced by the micromachined active mixer. By ejecting reaction mixture onto the capture zone through micromachined fluid ejector array, the fluorescent tagged analytes bind with capturing antiodies on capture zone. The fluid ejector array further ejects buffer fluid to wash away unbound fluorescent tags.

After many decades, 1-Naphthylisocyanate (NIC) has been identified as the most ideal pre column derivatization fluorescent tag for reversed phase Liquid Chromatographic (HPLC) analysis of all free amino acids (AA) in biological samples. NIC forms very stable derivatives with all AAs in one minute. Using NIC, the first, most simple, robust, sensitive (femto mole), and economical high pressure binary gradient, HPLC method, has been developed. It estimates 35 (and 2 internal standards) AAs in human plasma in record shortest time of 20 minutes and has been validated for precision (n=16, <6%), accuracy 95 %, linearity (0 to 1200 μM/L), and analyzing normal and abnormal patients. It can provide with in 20 minutes the first and best plasma free AAs profile that includes Homocysteine, Cysteine, Alloisoleucine, and Cystathionine and a 27 AAs profile using a blood spot (3 μl plasma). A sample can be analyzed with in one hour of its arrival in the laboratory.

The present disclosure relates to semiconductor devices for detecting fluorescent particles. At least one embodiment relates to an integrated semiconductor device for detecting fluorescent tags. The device includes a first layer, a second layer, a third layer, a fourth layer, and a fifth layer. The first layer includes a detector element. The second layer includes a rejection filter. The third layer is fabricated from dielectric material. The fourth layer is an optical waveguide configured and positioned such that a top surface of the fourth layer is illuminated with an evanescent tail of excitation light guided by the optical waveguide when the fluorescent tags are present. The fifth layer includes a microfluidic channel. The optical waveguide is configured and positioned such that the microfluidic channel is illuminated with the evanescent tail. The detector element is positioned such that light from activated fluorescent tags can be received.

The present invention provides novel fluorescent compounds and covalent attachment chemistries which facilitate the use of these compounds as labels for ultrasensitive and quantitative flourescent detection of low levels of biomolecules. In a preferred embodiment, the flourescent labels of this invention are novel derivatives of the hydroxy-pyrene trisulphonic and disulphonic acids which may be used in any assay in which radioisotopes, colored dyes or other fluorescent molecules are currently used. Thus, for example, any assay using labeled antibodies, proteins, oligonucleotides or lipids, including fluorescent cell sorting, fluorescence microscopy (including dark-field microscopy), fluorescence polarization assays, ligand, receptor binding assays, receptor activation assays and diagnostic assays can benefit from use of the compounds disclosed herein.

The contrast of an image produced by epifluorescence microscopy may be increased by placing a high-pass dichroic reflecting film behind the sample. The reflecting film reflects the emission light emitted by the fluorescent tags in the sample back through the objective lens while allowing the shorter wavelength excitation light to pass through the sample holder.

The present invention relates to a method for detecting antibodies against a target antigen in a sample which comprises contacting the sample with labelled target antigen, subjecting the sample to immunoprecipitation to precipitate antibodies in the sample and detecting the presence of antibodies against the target antigen in the sample by means of the presence of labelled target antigen in the immunoprecipitate, wherein the labelled target antigen is a fusion protein comprising the target antigen and a fluorescent protein label and the presence of labelled target antigen in the immunoprecipitate is detected by means of the fluorescence of the fluorescent label. The method is particularly suitable for use where the target antigen is an autoantigen and can also be used to identify autoantigens implicated in a particular autoimmune disorder by screening serum samples from patients with a clinical phenotype indicative or suggestive of an autoimmune disorder and suitable controls. The target protein may be from the cys-loop acetyl choline receptor ion channel gene superfamily, the voltage-gated calcium, sodium or potassium ion channel gene superfamily, the glutamate receptor gene family, a receptor tyrosine kinase, or other membrane associated channels such as aquaporin gene family.