41 results about "Chemical labeling" patented technology

The invention provides a new method for double quantifying the protein group marked on the basis of stable oxygen isotope <18>O, which is characterized in that: based on the fact that the N end peptide section and the C end peptide section are generally labeled, and by means of combining the <18>O chemical labeling and enzyme digestion, the quantifying strategy for two <18>O markings of the same sample can be accomplished. The method relates to the reductive alkylation and enzyme digestion of protein, dual-functional reagent modifying and <18>O marking of peptides, multi-dimensional liquid phase chromatogram separation and multistage Tandem Mass Spectrometry quantification and identification. A first mass spectrum peak area is used to quantify; and the identification of the protein is conducted through a second stage mass spectrum and by searching the database. The invention also provides a reagent box for facilitating the implementation of the method.

The invention relates to the field of biotechnology. A vascular endothelial cell grow factor (VEGF) plays an important function in the regeneration and hyperplasia of blood vessels; but the VEGF in the body has low content and a short half life; therefore, sufficient endogenous VEGF protein is hardly extracted to meet the ever growing experimental study and clinical requirements. The invention discloses a method for economically and conveniently preparing, extracting, purifying and recombining the VEGF protein of a human body through a recombination gene engineering and immunity affinity column method. The invention also discloses a method for carrying out the in-vitro non-radioactive chemical coupling label processing of the purified VEGF protein. The VEGF protein (including the protein having no label or having the chemical coupling label) can be widely applied to experimental study and clinical diagnosis and treatment.

The invention discloses a protein isotope dilution tandem mass spectrometry method based on a chemical labeling technology. The method comprises (1) labeling a sample to be detected by a chemical label A to obtain a labeled sample, (2) labeling an internal standard substance with a chemical label iso-A with an isotope label to obtain a labeled internal standard substance, (3) uniformly mixing the labeled sample and the labeled internal standard substance according to a preset ratio to obtain an initial sample, (4) pretreating the initial sample to obtain a fed sample, and (5) carrying out mass spectrometry on the fed sample. The sample and internal standard substance are respectively labeled, then are mixed, then added into a reaction system and then are treated so that the sample and internal standard substance are subjected to the same matrix effect and have the same operation error in the same system and thus the error can be corrected.

The invention provides a mass spectrum detection method for interaction between an active protein and a small molecule. According to the method, in-vivo covalent chemical labeling is performed on a protein while the active state is maintained; and the site and the intensity of the interaction between a small molecule and the protein are judged through the difference in the labeling efficiency before and after the interaction between the specific amino acid position on the protein and the small molecule. According to the present invention, with the mass spectrum detection method, the protein inhibitor candidate small molecule can be subjected to high-throughput screening, and the potential protein target of the specific small molecule can be subjected to large-scale identification analysis;and through the large-scale identification analysis of the Catechol-O-methyltransferase (COMT)-small molecule interaction and the ATP-binding protein in the complex system biological system, the method has accuracy and high efficiency.

A method and engineered proteins for use therewith suitable for studying SERCA that are capable of being used in vivo and do not require protein purification or chemical labeling of SERCA, or reconstitution into artificial membranes. The engineered protein for calcium handling within human cells includes a two-color SERCA construct having three component proteins fused together. The three component proteins include a blue fluorescent protein (cerulean), SERCA2a and a yellow fluorescent protein (YFP), or a red fluorescent protein (tagRFP acceptor), SERCA and a green fluorescent protein (GFP). The method of determining SERCA activity for optimization of cardiac function includes resolving structure changes of the two-color SERCA construct. The two-color SERCA constructs are catalytically active and able to pump calcium following the step of resolving structure changes.

The invention provides a bioluminescent detection probe based on a transcriptional activator like effector. The probe can achieve bioluminescence detection of microRNA (miRNA) without chemical labeling. The probe is a monomeric protein, and includes the following three parts: 1) a transcriptional activator like effector domain capable of specifically recognizing a DNA-miRNA hybrid chain; 2) a luciferase domain with bioluminescence; 3) a connecting region of the above two domains. The probe uses a single-stranded DNA coupled to the surface of a magnetic bead to hybridize with the miRNA to be tested, and a DNA-miRNA hybrid chain produced by hybridization is specifically recognized by the bioluminescent probe formed by the transcriptional activator like effector and the luciferase domain to achieve high sensitivity detection of the miRNA. The probe has the advantages of being low in cost, intuitive in result and convenient to use.

The invention belongs to the field of researches of microcosmic conformation of proteins by utilizing a proteomic analysis technology, relates to a method for detecting conformational changes of the proteins by a mass spectrometry technology and in particular relates to a method for detecting the conformational changes of the proteins by combining active covalent chemical labeling and the mass-spectrometry technology. Lysine residues are subjected to the active chemical labeling from the whole level of the proteins; then protein denaturation and enzymolysis are carried out and then a mass spectrometry is used for detecting; the labeling efficiency of the lysine residues is calculated through an identification result of the mass spectrometry. The method is rapid and simple, is stable and efficient and can be used for inspecting the fine conformational changes of protein structures; in a labeling process, the activity of the protein keeps unchanged and the labeling process is not limited by the size, solubility and purity of the proteins and the like; the conformation of the proteins under a physiological activity state can be reflected more really.

The invention discloses a fluorescence labeling biological material and a preparation method thereof. The method comprises the following steps: (1) activating fluorescent molecules; (2) carrying out areaction on a polymer and activated fluorescent molecules; (3) dialyzing the solution after the reaction in the step (2) with deionized water, and freeze-drying to obtain a fluorescence labeling biological material, wherein the polymer is a polyamino acid-based polymer or a chitosan-based polymer. According to the invention, the carboxyl on a fluorescent molecule is activated into active ester, then the active ester and the amino on a biopolymer are subjected to an amidation reaction, and the fluorescent molecule is chemically coupled to the biopolymer, so that the fluorescence labeling material has different fluorescence colors due to different labeled fluorescence molecules, and the chemical labeling method avoids the defect that fluorescent molecules or particles thereof are easy to diffuse out of a system in physical mixing or electrostatic adsorption and other methods; and the fluorescence labeling biological material has a wide application prospect in the research fields of in-vitro and in-vivo imaging, tracing, material degradation, biosensing, 3D printing and the like.

The invention discloses a DNA aptamer specifically combined with human breast cancer cells MCF-7. The nucleotide sequence of the DNA aptamer is shown by any one or several sequences in SEQ ID NO:1 toSEQ ID NO:4, or is obtained through chemical modification, chemical labeling or basic group change on any one sequence in SEQ ID NO:1 to SEQ ID NO:4. The invention also discloses application of the DNA aptamer or the nucleotide sequence to diagnosis reagents, molecular imaging probes or target media. The invention also relates to a human breast cancer detection and diagnosis kit, which has wide application prospects in breast cancer detection, diagnosis and treatment. The DNA aptamer related by the invention has the advantages of high affinity, high specificity, small molecular weight, high stability, synthesis simplicity, low cost, simplicity in modification, no immunogenicity and the like, and can meet the requirement of human breast cancer fast diagnosis at present.

A method and apparatus for measuring binding between a plurality of molecules of a biological receptor protein and a plurality of molecules of a type which binds to said biological receptor is presented. Apparatus utilizes a sensor possessing a waveguide to which have been attached in close proximity to its surface, features resembling molecules having binding affinity for said biological receptor. Light is injected into said waveguide so as to produce an evanescent field at its surface. Molecules of receptor protein are tagged with a tag belonging to that class of chemicals which alters a characteristic of light, when said light passes through said chemical tag. Apparatus utilizes a rapid means of monitoring the change in optical signal coming from the waveguide as binding proceeds between tagged receptor protein and the binding molecular feature of the waveguide. This allows direct measurement of binding and dissociation rates between the receptor and the binding feature of the waveguide. By using a waveguide having a feature resembling a ligand for the receptor, the potential hormonal activity of a test substance may be evaluated from its ability to compete with the waveguide for binding with the receptor. The effect of a test compound on binding of receptor protein to a subsequent element in a hormonal signal transduction mechanism is evaluated by measuring the impact of the test compound on binding between receptor protein and a feature resembling said next element of the signal transduction mechanism. Methods are provided whereby such data may be used to compute affinity constants, binding activity, complex affinity constants resulting from cooperativity, and kinetic parameters for the receptor and test ligand and for the receptor and the next element of the signal transduction mechanism. Preferred embodiments of the invention illustrate application of the method and apparatus to measuring binding between biological receptors and their nuclear response elements, and the use of this type of measurement for assessment of the activity of estrogen mimics present in a test sample, and for evaluation of pharmaceuticals intended to treat hormone dependent cancers.

The invention relates to the technical field of biotechnology, and specifically relates to a p16 immune cell chemical labeling color-developing kit. The detection kit comprises the following reagents:0.5-1.0 ml of a p16 immune cell standard substance with the concentration of 81 pg/mL, 1.5 to 2.0 ml of a standard substance diluent, 2-4 ml of horseradish peroxidase, 2-4 ml of a sample diluent, 2-4ml of a color-developing agent solution A, 2-4 ml of a color-developing agent solution B, 2-4 ml of a stop solution, and 20ml of 20 times of concentrated washing solution. The method comprises the steps of coating a microporous plate with a purified human p16 antibody to prepare a solid-phase antibody, adding p16 into micropores coated with a monoclonal antibody, combining with a horseradish peroxidase-labeled p16 antibody to form an antibody-antigen-enzyme-labeled antibody compound, thoroughly washing, and then adding a color-developing agent A substrate for color development. The color-developing agents A and B are converted into blue under the catalysis of horseradish peroxidase and converted into final yellow under the action of acid, the positioning effect and the color-developing effect are good, the labeling is more obvious, the color depth is in positive correlation with p16 in a sample, and the absorbance is measured by using a microplate reader at the wavelength of 450 nm.

The invention relates to the technical field of cell chromogenic reagents, in particular to an immune cell chemical labeling chromogenic kit for auxiliary diagnosis of cervical cancer. The kit comprises a ready-to-use antibody working solution, a reagent solution C, a reagent solution D, a reagent solution E, a reagent solution F and a reagent solution G; the ready-to-use antibody working solution comprises an antibody reagent, bovine serum albumin, non-reducing sugar, fish skin gelatin, a preservative proclin-950, tender leaf green pigment, polyethylene glycol, casein, a surfactant, 4-aminoantipyrine and sodium chloride, and the antibody reagent comprises a reagent solution A and a reagent solution B. The kit can be used for cervical decellularization and can also be used for tissue staining. The blue returning mode is newly created, the blue returning effect is better than that of kits of other manufacturers in the market, the sheet sealing mode is simpler, and the experiment time is greatly shortened.

The invention relates to a new structure analysis method for researching protein and material interaction based on chemical labeling and mass spectrometry technologies. The method is characterized inthat firstly proteins and protein-material complexes are chemically labeled, then denaturation, enzymatic hydrolysis, chromatography-mass spectrometry analysis and database retrieval of the proteins are carried out, and the change conditions of the chemical labeling efficiency of specific amino acid sites on the proteins before and after materials are added are compared, so that a region with theobviously reduced labeling efficiency is namely a protein-material interaction region and a region with the obviously improved labeling efficiency is namely a protein conformation change region afterthe materials are combined. The protein-material interaction analysis method has the advantages of being rapid and simple, stable and efficient, high in sensitivity and capable of realizing high-throughput dynamic analysis, the physiological structures and activities of the proteins are still kept in the labeling process, and an analysis result is not limited by conditions such as the molecular weight, the purity and the like of the proteins.

The present disclosure relates to a method for using chemical tags which have two or more sites for ionization to improve quantification and identification of components of interest from a complex mixture. This method relies on first selectively reacting one or more component in a sample with a chemical tag having two or more sites for ionization, followed by separation of components based on charge status, and finally characterization of each component to identify the same. Additionally disclosed are compounds useful as chemical tags in the disclosed methods.

The invention discloses nucleic acid aptamers for detecting extracellular vesicles of a human lung cancer cell strain A549. Nucleotide sequences of the nucleic acid aptamers are shown as SEQ ID NO: 4 (Ap3) and SEQ ID NO: 5 (Ap6). Or the nucleic acid aptamers are a series of derivatives which are obtained through chemical modification, chemical labeling or basic group change on the basis of SEQ ID NO: 4 (Ap3) and SEQ ID NO: 5 (Ap6) sequences. The nucleic acid aptamers disclosed by the invention can be applied to the recognition of extracellular vesicles of the human lung cancer cell strain or the preparation of a kit for detecting the extracellular vesicles of the human lung cancer cell strain or a combination of extracellular vesicle drug delivery and specific recognition of targets. The nucleic acid aptamers can be applied to identification of human lung cancer or preparation of the kit for detecting human lung cancer. The nucleic acid aptamers have very wide application prospects in detection, diagnosis and treatment of human lung cancer.

The invention discloses an < 18 > F-dodecane positron imaging agent and a preparation method thereof, is based on a positron nuclide chemical labeling method, and belongs to the field of industrial nondestructive testing. The invention discloses an < 18 > F-dodecane positron imaging agent and a preparation method thereof in order to overcome the defects of an existing marking scheme in accuracy and application range, so that the < 18 > F-dodecane positron imaging agent can determine that gamma photons are generated by burning kerosene instead of volatilized kerosene, the marking accuracy is realized, and the reliability is improved; secondly, the application range of the 18F-dodecane positron imaging agent is not only kerosene, but also can be used for detecting gasoline and aerospace kerosene, so that the application range of the 18F-dodecane positron imaging agent is expanded, and the applicability is improved; meanwhile, the finished product is subjected to structure confirmation and quality control experiment in the preparation process, so that the quality and accuracy of the < 18 > F-dodecane positron imaging agent are ensured.