50 results about "Thioflavin" patented technology

This invention relates to novel thioflavin derivatives, methods of using the derivatives in, for example, in vivo imaging of patients having neuritic plaques, pharmaceutical compositions comprising the thioflavin derivatives and method of synthesizing the compounds. The compounds find particular use in the diagnosis and treatment of patients having diseases where accumulation of neuritic plaques are prevalent. The disease states or maladies include but are not limited to Alzheimer's disease, familial Alzheimer's disease, Down's Syndrome and homozygotes for the apolipoprotein E4 allele.

Described is a new class of small molecule inhibitors of amyloid beta protein (Abeta) aggregation, based on apomorphine. These molecules target the nucleation phase of Abeta self-assembly and interfere effectively with aggregation of Abeta 1-40 into amyloid fibrils in vitro as determined by transmission electron microscopy, Thioflavin T (ThT) fluorescence, and velocity sedimentation. Structure-activity studies using apomorphine analogues demonstrate that 10,11-dihydroxy substitutions of the D ring are preferred for the inhibitory effectiveness of these aporphines, and that methylation of these hydroxyl groups reduces their inhibitory potency. The ability of these small molecules to inhibit Abeta amyloid fibril formation appears to be linked to their ability to undergo auto-oxidation in solution, implicating an auto-oxidation product as the active Abeta inhibitor. Sedimentation velocity and electron microscopy studies demonstrate that apomorphine and analogues facilitate oligomerization of Abeta into short nonfibrillar soluble assemblies, but inhibit Abeta fibrillization.

This invention relates to novel thioflavin derivatives, methods of using the derivatives in, for example, in vivo imaging of patients having neuritic plaques, pharmaceutical compositions comprising the thioflavin derivatives and method of synthesizing the compounds. The compounds find particular use in the diagnosis and treatment of patients having diseases where accumulation of neuritic plaques are prevalent. The disease states or maladies include but are not limited to Alzheimer's Disease, familial Alzheimer's Disease, Down's Syndrome and homozygotes for the apolipoprotein E4 allele.

The invention relates to a method for constructing an in-vitro aggregation model of associated protein polyQ of Huntington`s disease, which comprises the following steps: constructing an expression vector of fusion protein GST-polyQ(Q36-Q55); making the expression vector express the fusion protein GST-polyQ(Q36-Q55) in expression bacteria; purifying expression products by affinity chromatography to obtain fusion protein GST-polyQ(Q36-Q55); using protease for enzyme cutting to remove the GST tag from the fusion protein GST-polyQ(Q36-Q55) to obtain a polyQ polypeptide; refrigerating and drying the obtained polyQ polypeptide; preparing a polyQ polypeptide solution; carrying out an aggregation reaction on the polyQ polypeptide solution in PBS or Tris-HCl with the pH of 6.5-7.8; and inspecting the aggregation process of the polyQ polypeptide solution by Thioflavin T. The model constructed by the method can be used for screening and dynamics study of active substances preventing Huntington's disease. Compared with artificially synthesized polyQ polypeptide, the method is capable of largely reducing cost for screening active substances.

The invention discloses a high salt tolerant colorimetric sensor based on functional nucleic acid of zinc and application thereof. The high salt tolerant colorimetric sensor includes a molecular recognition element, a signal amplification element, and a signal conversion element. The molecular recognition element consists of zinc ion deoxyribozyme, which is composed of a substrate chain and an enzyme chain. The signal amplification element includes an isothermal amplification system, and the isothermal amplification system also includes an amplification template. The signal conversion elementincludes thioflavin. The molecular recognition element recognizes zinc ions and produces an amplification product, the amplification product forms a G-quadruplex structure under the action of thioflavin, and the fluorescence intensity is detected to calculate the zinc ion concentration. The sensor provided by the invention is based on zinc ion deoxyribozyme, isothermal index amplification reactionand G-quadruplex liquid phase sensing technology, can be used for field detection of zinc ions in the environment, and has the advantages of simple and rapid operation, low cost, high sensitivity andgood selectivity.

The invention belongs to the field of analysis and detection, which relates to a method for photoelectrochemically detecting aflatoxin based on a homogeneous anode of bismuth tungstate. An ITO electrode modified by bismuth tungstate is used as a photoanode, and signal molecules (methylene blue or thionein T) can be used as electron donors to increase the photocurrent of the anode. In a homogeneoussolution, in combination with a rolling circle amplification (RCA) reaction mediated by an aflatoxin and aptamer recognition reaction and the characteristic that signal molecules are specifically embedded into a G-quadruplex, a signal enhanced detection platform is constructed. According to the present invention, the aflatoxin detection sensitivity is high, a linear range is 0.01-10000 pg/mL, andthe detection limit is as low as 2.6 fg/mL. Compared with the traditional method, the method provided by the invention has the advantages of low cost, simplicity and convenience in operation (no needof marking and electrode fixation of biomolecules), small reagent dosage and high practicability, and is expected to become one of efficient methods for detecting aflatoxin.

The invention discloses a colorimetric sensor for cadmium-based functional nucleic acid and application of the colorimetric sensor in the technical field of metal ion detection. The colorimetric sensor comprises a molecular recognition element, a signal amplification element and a signal conversion element, wherein the molecular recognition element comprises a cadmium ion deoxyribozyme, and the cadmium ion deoxyribozyme comprises a substrate chain and an enzyme chain; the signal amplification element comprises an isothermal amplification system, and the isothermal amplification system comprises an amplification template; the signal conversion element comprises a thioflavin. The colorimetric sensor is based on the cadmium ion deoxyribozyme, equivalent temperature index amplification reaction and the G-quadruplex liquid phase sensing technology, the molecular recognition element recognizes cadmium ions and generates amplification products, and a G-quadruplex structure is formed by the amplification products under the action of thioflavin. The concentration of the cadmium ions is calculated by detecting the fluorescence intensity, and the colorimetric sensor has the advantages of being simple, quick, high in sensitivity, high in specificity, high in salt resistance, low in cost and the like and can be used for on-site detection of the cadmium ions in the environment.

The invention belongs to the biotechnological field and particularly relates to a method for detecting miRNA. The method comprises the steps that S1, a DNA molecular machine for specific recognition of miRNA is provided, the DNA molecular machine contains a nucleotide sequence of complementary sequences of a G-four-stranded-body sequence; S2, the DNA molecular machine and a sample to be detected are mutually recognized; S3, DNA polymerase and nickase are introduced to act on the DNA molecular machinery; S4, thioflavin T is introduced to induce production of the G-four-stranded-body structure and combination with a G-four-stranded-body; S5, the fluorescence radiation situation is recorded. The DNA molecule generating machine is a nucleotide sequence consisting of zones arranged in sequencefrom 3' to 5', namely a miRNA sequence recognition zone, a stable zone, nickase recognition zone and a G-four-stranded-body synthesis template. The method does not need fluorescent probe labeling, hashigher sensitivity and is simpler in operation.

The invention provides a method for detecting iodide ions by an unmarked fluorescent probe based on thioflavin T dye design. The method comprises the steps of adding a buffer solution into the prepared thioflavin T/deoxyribonucleic acid (DNA)/ Hg<2+> unmarked fluorescent probe, and adding iodine ion solutions with different concentrations into reaction liquid for carrying out a reaction; measuring a fluorescence value of the mixed liquid, and establishing an equation for detecting the solubility of the iodide ions in unknown liquid under test. After the method is used, the currently common detection mode for detecting the iodide ions is changed, and the iodide ions are detected by an unmarked fluorescent probe technology for the first time, so that the defects that the existing detection method is low in sensitivity and complicated in operating steps, needs expensive large-scale instruments, is difficult in realization of rapid on-line detection, and the like can be overcome; the method has the advantages of being rapid in detection response, high in sensitivity, good in selectivity and the like, is a proper, effective and practical detection method, and can be applied to determination of the iodide ions in practical samples.

The present invention provides a method for determining the stoichiometric ratio of the amyloid protein and the base which will result in a linear relationship between the amount of amyloid protein and the Thioflavin T fluorescence. Suitable stoichiometric ratios of the amyloid protein to base (such as 10 mM NaOH) of 1 μg:1 μl to 1 μg:1.25 μl can then be used in a Thioflavin T assay to identify potential agents which can inhibit or reduce amyloid protein fibril aggregation.

A method of screening a blood sample for the presence of prions. The method includes the steps of collecting the blood sample in heparin, contacting the sample with a solution comprising recombinant prion protein (rPrP) and Thioflavin T (ThT), and measuring the resulting ThT fluorescence in the sample. The method can further include the step of freezing and thawing the sample prior to contacting the sample with a solution comprising recombinant prion protein (rPrP) and Thioflavin T (ThT). The method can also include the step of precipitating the prions in sodium phosphotungstic acid (NaPTA) prior to contacting the sample with a solution comprising recombinant prion protein (rPrP) and Thioflavin T (ThT).

[Problems] To enable convenient and accurate examination of Alzheimer's disease.

[Means for Solving Problems] A reaction liquor, which is prepared by mixing an amyloid β protein with a body fluid collected from a subject and a buffer solution is reacted. After the polymerization of the amyloid β protein comes to equilibrium, the degree of the amyloid β protein polymerization is examined. For example, the above-described reaction liquor is mixed with a fluorescent dye after the completion of the reaction and the degree of the color-development of the reaction liquor is detected to thereby examine the degree of the amyloid β protein polymerization. The fluorescent dye as described above is thioflavin T or its derivative. The body fluid as described above is cerebral fluid, blood or a blood component.

A green fluorescent protein-based nanoparticle, a preparation method and an application thereof in cell imaging and cell nucleus nucleolar staining belong to the field of fluorescent protein-based nanomaterials. The method includes the steps of adding a concentration thioflavin-T aqueous solution as a building molecule in deionized water, adding a bovine serum albumin or human serum albumin aqueous solution, heating the solution and finally cooling the solution to the room temperature to obtain a green fluorescent protein-based nanoparticle T-FPNs solution. An experiment with Hela cells in yeast cells shows that T-FPNs can be used as bioimaging materials and nucleolar localization dyes. The nanoparticle is suitable for large-scale production because a synthesis method is cost-effective, environmentally friendly, simple and biocompatible. The T-FPNs with excellent light stability can stain nucleoli of live cells and fixed cells nucleoli for fast real-time no-clean imaging.

The invention provides a one-step fluorescence detection system and a thrombin detection method, and relates to the technical field of analytical chemistry. The detection system comprises a B-H2 functionalized nano-fiber membrane, support DNA, output DNA, competitive DNA, a buffer solution, thioflavin T (ThT), an H1 sequence and thrombin. When the detection system is used for detecting the thrombin, based on the improvement of reaction thermodynamics and kinetics on a surface interface of the nano-fiber membrane, the corresponding detection system has a detection limit of 1.0pM, and has a goodlinear relation between 50pM and 5nM, excellent selectivity and long-term stability. When the detection system is used for detecting a sample, a PiDSD process, CHA amplification and a ThT binding reaction are integrated, so that the separation and elution processes required by ELISA are avoided, the time is shortened, and the steps are simplified.

The invention discloses a method for label-free visual detection of vibrio parahaemolyticus genes based on CRISPR (clustered regularly interspaced short palindromic repeats)/Cas12a. A characteristic gene of vibrio parahaemolyticus is amplified through LAMP, a compound assembled by Cas12a and crRNA is utilized to recognize and is combined with a characteristic sequence on a specific product amplified by LAMP to activate the affiliated cleavage activity of Cas12a, so that a G quadruplex is cleaved, the G quadruplex cannot be combined with thioflavin T (ThT) and loses the fluorescence enhancement capability, and finally, gene information of the vibrio parahaemolyticus is converted into visible fluorescence change. According to the invention, specific, label-free and visual detection of the vibrio parahaemolyticus genes is realized.

A method of screening a blood sample for the presence of prions. The method includes the steps of collecting the blood sample in heparin, contacting the sample with a solution comprising recombinant prion protein (rPrP) and Thioflavin T (ThT), and measuring the resulting ThT fluorescence in the sample. The method can further include the step of freezing and thawing the sample prior to contacting the sample with a solution comprising recombinant prion protein (rPrP) and Thioflavin T (ThT). The method can also include the step of precipitating the prions in sodium phosphotungstic acid (NaPTA) prior to contacting the sample with a solution comprising recombinant prion protein (rPrP) and Thioflavin T (ThT).

The invention discloses an application of thioflavin-T to kit preparation, a method for determining presence of RNA G-quadruplex in a to-be-detected sample and a kit for detecting RNA G-quadruplex. The method for determining presence of RNA G-quadruplex in the to-be-detected sample comprises the following step: (1) the to-be-detected sample makes contact with thioflavin-T, a mixed solution is obtained accordingly, and the fact that the to-be-detected sample contains RNA is determined in advance; (2) the mixed solution is subjected to ultraviolet-visible absorption spectrum analysis; (3) whether RNA G-quadruplex is present in the to-be-detected sample is determined on the basis of an ultraviolet-visible absorption spectrum analysis result, wherein according to the ultraviolet-visible absorption spectrum analysis result, the maximum absorption peak of thioflavin-T is at 424-544 nm, which indicates that the to-be-detected sample contains RNA G-quadruplex. The method for determining presence of RNA G-quadruplex in the to-be-detected sample has the characteristics of being simple and convenient to operate, high in sensitivity and high in accuracy.

The invention discloses an application of thioflavin-T to preparation of a kit, a method for determining whether a discontinuous RNA G-quadruplex exists in a to-be-detected sample and a kit for detecting the discontinuous RNA G-quadruplex. The method for determining whether the discontinuous RNA G-quadruplex exists in the to-be-detected sample comprises the following steps: (1) the to-be-detected sample makes contact with thioflavin-T, a mixed solution is obtained, and the fact that the to-be-detected sample contains RNA is determined in advance; (2) fluorescence spectrum analysis is performed on the mixed solution; (3) whether the discontinuous RNA G-quadruplex exists in the to-be-detected sample is determined on the basis of a fluorescence spectrum analysis result. The method has the characteristics of being simple and convenient to operate and high in sensitivity and accuracy.

The invention discloses a fluorescent probe and application thereof to detection of five aromatic pesticides, according to the fact that a supramolecular compound generated by cucurbit [8] uril (Q [8]) and thioflavin T (ThT) can generate yellow fluorescence, and FBZ, CBZ, TBZ, TDZ and TCZ can make the yellow fluorescence blue shift and be enhanced, the fluorescent probe can be applied to detection of five aromatic pesticides. The supramolecular complex formed by Q [8] and ThT in a molar concentration ratio of 1: 1 is used as the fluorescent probe, so that five aromatic pesticides such as FBZ, CBZ, TBZ, TDZ and TCZ in the environment can be conveniently, quickly and sensitively detected.