675 results about "Fluorescent quenching" patented technology

A method for analyzing a blood sample is provided that includes the steps of: a) providing a blood sample having one or more first constituents and one or more second constituents, which second constituents are different from the first constituents; b) depositing the sample into an analysis chamber adapted to quiescently hold the sample for analysis, the chamber defined by a first panel and a second panel, both of which panels are transparent; c) admixing a colorant with the sample, which colorant is operative to cause the first constituents and second constituents to fluoresce upon exposure to predetermined first wavelengths of light, and which colorant is operative to absorb light at one or more predetermined second wavelengths of light; d) illuminating at least a portion of the sample containing the first constituents and the second constituents at the first wavelengths and at the second wavelengths; e) imaging the at least a portion of the sample, including producing image signals indicative of fluorescent emissions from the first constituents and the second constituents and the optical density of the first constituents and the second constituents; f) determining a fluorescence value for each the first constituents and second constituents using the image signals; g) determining an optical density value for each of the first constituents and second constituents, which optical density is a function of the colorant absorbed by the constituents, using the image signals; and h) identifying the first constituents and the second constituents using the determined fluorescence and optical density values.

The invention discloses a nitrogen-doped carbon nanometer particle as well as a preparation method and application thereof, belongs to the field of nanometer material science and is used for solving the technical problems that fluorescence quenching is easily caused to the aggregative state of the carbon nanometer particle due to surface passivation modifier which is added for the preparation of existing carbon nanometer particles. The nitrogen-doped carbon nanometer particle is prepared through a microwave method by using organic compounds containing polycarboxyl or polyhydroxy as materials and using ammonia water as a solvent and a nitrogen doping source. The invention further provides the application of the nitrogen-doped carbon nanometer particle as fluorescent ink and fluorescent glue. The preparation method disclosed by the invention is simple, low in cost, and convenient to realize large-scale production; the maximal fluorescent quantum efficiency of the solid film formed by the prepared fluorescent glue is as high as 84%; the prepared fluorescent ink is non-toxic, generates no precipitates after being placed for a long time, is strong in fluorescence characteristic and can be applied to various fields such as bio-imaging, biological product identification, information storage, information encryption, counterfeiting prevention, illumination and display, sensing and photovoltaic devices.

The invention discloses a multi-target quantum-dot mark nucleic acid chip and a preparation method and a detection method thereof, wherein the nucleic acid chip comprises a solid phase holder and an oligonucleotide probe array fixed on the surface of the solid phase holder, wherein the oligonucleotide probe array comprises at least two oligonucleotide probes which do not contain self-complementary sequences; one end of the oligonucleotide probe marks quantum dots and is fixed by the quantum dots, and the oligonucleotide probes with different sequences are marked by the quantum dots which emit fluorescence with different wavelengths; or the oligonucleotide probe array comprises at least two molecular beacons, wherein one end of the molecular beacon marks quantum dots and is fixed by the quantum dots, the molecular beacons with different sequences are marked by the quantum dots which emit fluorescent with different wavelengths, and the other end of the molecular beacon is marked by a fluorescence quenching group. By utilizing the basic-group complementation pairing principle and the FRET phenomenon, the detection of a plurality of special nucleic acid sequences in a nucleic acid sample to be detected can be simultaneously achieved; in addition, the invention has simple preparation and accurate, sensitive, simple, convenient and rapid detection and can detect a plurality of samples simultaneously.

The invention provides a pillar[5]arene and 2-hydroxy-3-naphthoic acid complex.Copolymerized pillar[5]arene serves as a subject, 2-hydroxy-3-naphthoic acid serves as an object, C-H......pi and electrostatic attraction serve as driving force, partial 2-hydroxy-3-naphthoic acid provided with negative charges is included into a cavity of pillararene in an alkaline environment, the assembling process of the subject and the object is completed, and the stable pillar[5]arene and 2-hydroxy-3-naphthoic acid complex is formed.Iron ions are added to an alkaline aqueous solution of the complex, and the subject and the object are subjected to fluorescence quenching; fluorine ions are added, a complex is formed by the fluorine ions and the iron ions, so that the iron ions are separated from the cavity of copolymerized pillar[5]arene, and molecular fluorescence of the complex is reopened.Therefore, Fe<3+> can be determined through the pillar[5]arene and 2-hydroxy-3-naphthoic acid complex, and F<-> can be continuously identified through fluorescence quenching of the solution.

A paper chip, a preparation method thereof and a detection method for biological molecules are provided. The paper chip includes a paper-based material, a fluorescent donor and a fluorescent quenching agent. A detection zone is arranged on the paper-based material, and the fluorescent donor material is secured within the detection zone of the paper-based material. The fluorescent donor material includes an up-conversion luminescence nano-material and a surface marker marked on the up-conversion luminescence nano-material. The fluorescence quenching agent includes an organic dye or a fluorescent receptor. The combination of the up-conversion luminescence analysis and the paper chip technology decreases the amount of reactants used, reduces testing costs, speeds up the reaction rate of the reactants, and increases the possibility of applying the paper chips to the clinical testing.

Fluorescent energy transfer dyes capable of moving between a more stacked configuration to exhibit fluorescent quenching and a more spaced configuration to exhibit fluorescence can be conjugated to a peptide epitope or nucleic acid for use in the detection of an unknown antibody in bulk solution. The resulting labeled peptide reagent can be used in an immunoassay procedure by placing it in bulk solution along with the unknown antibody to be detected. When the antibody binds to the peptide epitope, the pair of dyes carried by the peptide epitope will have their configuration altered from a stacked to an unstacked configuration and will exhibit a fluorescent increase in response thereto.

The invention discloses a reagent, detection method and application for the detection of African hog cholera virus. The reagent comprises a specific primer pair and a probe, upstream and downstream primers of the primer pair are respectively sequences shown in Seq ID No. 1 and 2, and the probe is a sequence shown in Seq ID No. 3 or its reverse complement sequence; in the probe sequence shown in the SEQ ID No.3, a 28th base modifies fluorescent quenching group-dT, a 31st base is replaced with a base analog, a 33rd base modifies a fluorescent group-dT, and a 3' end modifies C3 Spacer. The reagent is sensitive, specific and efficient for detection of the African hog cholera virus by recombinase polymerase amplification; compared with conventional conventional or real-time fluorescent PCR, thereagent and the detection method have short detection time and simple operation, are especially suitable for on-site testing, and are of great significance for the rapid prevention and control of theAfrican hog cholera virus and guarantee of production safety.

The invention relates to the field of detection and analysis of lead ion concentration and discloses a lead ion fluorescent DNA (Deoxyribose Nucleic Acid) probe. The lead ion fluorescent DNA probe comprises double strands formed by hybridizing 17E deoxyribozyme with a substrate strand, wherein the tail end of the substrate strand is modified by FAM (Carboxyfluorescein). The invention also discloses a fluorescent determination method for the lead ion concentration by using the probe. The fluorescent detection of the lead ion concentration of a sample to be detected is carried out by taking the lead ion fluorescent DNA probe as an identification element of a lead ion, the FAM for modifying the tail end of the substrate strand as a fluorescent signal molecule and a colloidal gold nanoparticle as a fluorescence quencher according to the fluorescent signal difference generated when the FAM and the lead ion fluorescent DNA probe are subjected to single-double-strand combination. The fluorescent determination method disclosed by the invention has the advantages of high sensitivity, favorable selectivity for the lead ion, low cost, convenience in operation, quickness in detection and the like.

Oligonucleotide probes containing two labels are provided and are useful in hybridization assays. The probes can also contain a minor groove binding group.

The invention discloses fluorescent quantitative PCR (polymerase chain reaction) primers and probes for porcine epidemic diarrhea viruses. An upstream primer and a downstream primer are shown as SEQIDNO: 1-2; a probe P1 is shown as SEQIDNO: 3; a probe P2 is shown as SEQIDNO: 4; the 3' end of sequences of the probe 1 and the probe 2 are combined with a fluorescent quenching group; and the 5' end of sequences of the probe 1 and the probe 2 are combined with different fluorescent reporter groups. The primers are relatively high in specificity and sensitivity, can detect out variant PEDV (porcine epidemic diarrhea viruses), and can detect and differentiate a variety of clinical samples so as to quickly differentiate epidemic PEDV strains; the operation is simple and practical.