171 results about "Molecular biology" patented technology

The invention relates to a method for manufacturing a recombinant polyclonal protein composition, in particular a recombinant polyclonal antibody composition. The method comprises obtaining a collection of cells transfected with a library of variant nucleic acid sequences, wherein each cell in the collection is transfected with and capable of expressing one member of the library, which encodes a distinct member of a polyclonal protein that binds a particular antigen and which is located at the same single site in the genome of individual cells in said collection, wherein said nucleic acid sequence is not naturally associated with said cell in the collection. The cells are cultured under suitable conditions for expression of the polyclonal protein, which is obtained from the cells or culture supernatant. The nucleic acid sequence id introduced into the cells by transfection with a library of vectors for site-specific integration. The present method is suitable for manufacturing recombinant polyclonal antibodies, thereby mailing available a superior replacement of plasma-derived therapeutic immunoglobulin products.

The invention relates to the technical field of cell culture, and in particular to a serum-free culture medium, a preparation method thereof and a culture method of mesenchymal stem cells. The culturemedium consists of the following components: non-essential amino acid, glutamine, hydrocortisone, dexamethasone, polyvinyl alcohol, recombinant human insulin, recombinant human transferrin, a recombinant human epidermal growth factor, a recombinant human basic fibroblast growth factor, a recombinant human Wnt-3a protein, a recombinant human fibronectin, recombinant human laminin, L-glutathione, L-ascorbic acid, beta-mercaptoethanol, ethanolamine, Pluronic F-68, Tween 80, cholesterol, adenine, sodium selenite and a basic culture medium. According to the invention, polyvinyl alcohol can replaceserum albumin in a serum-free culture medium in carrier function, so that proliferation capacity of mesenchymal stem cells is effectively improved. Polyvinyl alcohol has more stable performance thanserum albumin, and the problem that proliferation capacity and passage capacity of stem cells are reduced can be effectively solved.

The invention discloses a CRISPR-Cas12a detection primer group for francisella tularensis and an application thereof. The invention provides the primer group for detecting francisella tularensis and is composed of an RPA primer pair and crRNA; the RPA primer pair is designed according to the nucleotide sequence shown in SEQ ID NO.1 in the francisella tularensis genome; the crRNA comprises an anchoring sequence and a guide sequence, wherein the anchoring sequence can be combined with a cas protein, and the guide sequence is matched with an amplification product sequence of an RPA primer pair. The detection primer group has the characteristics of short detection time, high amplification efficiency, high sensitivity, strong specificity and the like, and the detection sensitivity on francisella tularensis positive plasmids can reach 900 copy/ml, and the detection sensitivity on the francisella tularensis genome can reach 1260 fg/mL. The francisella tularensis onsite diagnosis method has awide application prospect.

The invention belongs to the technical field of biology, and particularly relates to a characteristic polypeptide for identifying the deer-horn glue of Cervus nippon or Cervus elaphus, and application of the characteristic polypeptide. The characteristic polypeptide provided by the invention is as follows: a peptide fragment 1 is as shown in SEQ ID No. 1: ASTGAALVVR; and a peptide fragment 2 is as shown in SEQ ID No. 2: TPVGQGPSVPVPNR. The characteristic polypeptide and the detection method provided by the invention provide reference for searching a characteristic peptide fragment in related species lacking in a database. The characteristic polypeptide provided by the invention has excellent specificity and stability for the deer-horn glue of the Cervus nippon or the Cervus elaphus, is high in specificity, can be used for identifying deer-horn glue medicinal materials and Chinese patent medicines added with the the deer-horn glue medicinal materials, and has a good application prospect.

The invention discloses multipath composite neuraminic acid producing bacillus subtilis and an application thereof, and belongs to the field of genetic engineering. The expression levels of key enzymes, namely UDP-N-acetylglucosamine-2-epimerase, N-acetylglucosamine-6-phosphate isomerase, glucosamine-6-phosphoric acid-N-acetyltransferase, N-acetylglucosamine isomerase and N-acetylneuraminate synthase on genomes in three neuraminic acid synthesis paths are sequentially optimized by 10 promoters with different intensities, so that the protein synthesis pressure of enzyme expression on cells is reduced; and three neuraminic acids are further integrated into the same engineering bacillus subtilis, so that the bacillus subtilis with the increased N-acetylneuraminic acid yield is obtained, the neuraminic acid yield under the shake flask level reaches 10.4 g/L, and a foundation is laid for further increasing the NeuAc yield of the bacillus subtilis.

Methods and devices for microfluidic detection of a biological maker in a biospecimen collected from a subject are disclosed. The microfluidic devices include nanoparticle-based nanosensors comprising supramolecular recognition sequences, protease consensus sequences, post-translationally modifiable sequences, or sterically hindered benzylether bonds for specific interaction with a biological marker. Also disclosed are particular nanosensors for detecting cytokines, and other proteins based upon supramolecular recognition without chemical modification or enzymatic cleavage.

The invention relates to the technical field of virus detection, and particularly discloses a novel coronavirus 2019-nCoV double-target antibody detection microsphere complex combination, a preparation method, a kit and a using method of the kit. A microsphere complex combination coupled with an antigen is used; the coupling antigen comprises an S protein of the novel coronavirus 2019-nCoV and anN protein of the novel coronavirus 2019-nCoV, the amino acid sequence of the S protein is as shown in SEQ NO: 1, and the amino acid sequence of the N protein is as shown in SEQ NO: 2. The prepared microsphere complex combination can perform double-target detection on an S antibody and an N antibody, and fully reflects the effect that two main antigens of the novel coronavirus (2019-nCoV) stimulatean organism to generate a specific antibody.

The invention provides a method for preparing autologous hematopoietic stem cells. The method includes following steps of cultivating somatic cells in a cell culture fluid for 3-6 days and collecting the generated autologous hematopoietic stem cells. The cell culture fluid is an RPMI1640 culture fluid containing: 1-100 [mu]M of Y-27632 (C14H21N3O.2HCl), 1-100 ng/ml of stem cell factors, 1-100 ng/ml of interleukin 3, 1-100 ng/ml of interleukin 6, 1-100 ng/ml of interleukin 11, 1-100 ng/ml of a macrophage colony stimulating factor (M-CSF), 1-100 ng/ml of a granulocyte colony-stimulating factor (G-CSF), 1-100 [mu]g/ml of fucoidin, 1-100 [mu]g/ml of dextran sulfate, 1-100 nM of AMD3100 (1,1'-[1,4-phenylenebis(methylene)]-bis-1,4,8,11-tetrazacyclotetradecane), 1-100 [mu]M of M-alendronate sodium (Malendronate sodium trihydrate), and 1-100 [mu]M of disodium pamidronate. The invention provides a method for preparing the autologous hematopoietic stem cells, a kit, the stem cells and an application. In addition, the method is advantaged in yield, purity, and producing speed of the production of the protein-induced autologous hematopoietic stem cells.

The invention discloses a mutant gene OsABCC1 for regulating and controlling cadmium and arsenic accumulation of rice and application of the mutant gene OsABCC1. According to the mutant gene OsABCC1 for regulating and controlling cadmium and arsenic accumulation of rice, a first base behind a tenth exon of a wild type OsABCC1 gene is subjected to variable shear mutation, namely, a base at a 2261 nucleotide at the downstream of ATG is mutated into A from wild type G, so that 1116 to 1131 nucleotides in a corresponding coding nucleotide sequence are deleted, a mutant is deleted and changed at 372<nd> to 382<nd> amino acids and is translated at a 383<rd> amino acid to be terminated in advance, the coding nucleotide sequence is shown as SEQ ID No.1, and the cadmium and arsenic contents inrice grains of the mutant hca1 are higher than those in wild type rice grains. The amino acid sequence coded by the mutant gene OsABCC1 is shown as SEQ ID No. 2. According to the application of the mutant gene OsABCC1, the rice contains the mutant gene OsABCC1 or contains the coding amino acid of the mutant gene OsABCC1. The cadmium and arsenic contents in the grains of the obtained mutant material hca1 are respectively increased by about 1 time and 5 times.

The invention provides compositions comprising and methods of using antigen presenting cells into which has been introduced at least a first nucleotide sequence that encodes calnexin, wherein expression of calnexin in the antigen presenting cell increases the antigen presenting cell's ability to activate a T cell response.

The invention discloses a culture medium for hepatoma organ cell sphere culture. The culture medium is composed of a basic culture medium, 10-25 ng/mL of an epidermal growth factor, 10-25 ng/mL of a fibroblast growth factor, 0.5-2 ng/mL of a cell growth factor, 1-3 ng/mL of an insulin growth factor, 1 mmol/L of sodium pyruvate, 2 mmol/L of glutamine, 100 U/mL of penicillin, 100 [mu]g/mL of streptomycin and 10% by volume of serum. Aiming at the culture growth characteristics of liver cancer tissue-derived cells, the culture medium provided by the invention is simple and reasonable in components, rich in nutrition and moderate in formula price; and hepatoma organ cell spheres cultured by the culture medium can effectively and stably grow for a long time, are closely gathered, have smooth andround surfaces and clear boundaries, is free of disintegration phenomenon, and can be significantly improved in cell activity, specific functions and metabolic functions.

The invention discloses PCR (polymerase chain reaction) detection primers for three bacteria and the application of the PCR detection primers. The three bacteria are alicyclobacillus aacillus, escherichia coli and salmonella. The upstream detection primer of the alicyclobacillus aacillus has the SEQIDNO.1, and the downstream detection primer has the SEQIDNO. 2. The upstream detection primer of the escherichia coli has the SEQIDNO.3, and the downstream detection primer has the SEQIDNO.4. The upstream detection primer of the salmonella has the SEQIDNO.5, and the downstream detection primer has the SEQIDNO.6. The multiple PCR detection method provided by the invention has the biggest advantages that the one PCR tube can be used for detecting three bacteria, the PCR detection efficiency is improved, and the errors caused by misoperation during detection are reduced.

Compounds having activity as inhibitors of G12C mutant KRAS protein are provided. The compounds have the following structure (I): or a pharmaceutically acceptable salt, stereoisomer, isotopic form or prodrug thereof, wherein R¹, L¹, L², L³, A¹, A², A³, A⁴, G¹, G², E, W, X, Y, Z, m, and n are as defined herein. Methods associated with preparation and use of such compounds, pharmaceutical compositions comprising such compounds and methods to modulate the activity of G12C mutant KRAS protein for treatment of disorders, such as cancer, are also provided.

The invention provides a building method for a rice male-fertile controllable line, comprising the following steps of: (a) obtaining the sterile mutant line of rice male-fertile genes and the corresponding functional male-fertile genes; (b) building a functional male-fertile gene expression cassette conversion carrier controlled by an inducible promoter; and (c) converting the sterile mutant line by the expression cassette conversion carrier, so as to obtain the rice male-fertile controllable line. The male-fertile controllable line built by the method provided by the invention can induce recombinant fertile gene expression by virtue of a corresponding inducer, thus realizing fertile selfing breeding; and the male-fertile controllable line represents complete male sterility in the case that the inductor is not applied, thus being capable of being hybridized with the male parent to produce hybrid seeds. Via the breeding method, the defects of breeding for three-line hybrid rice based on cytoplasmic male sterility, breeding for two-line hybrid rice based on photo-thermo-sensitive genic male sterile line, and methods for creating a sterile line by virtue of other genetic engineering methods are overcome.

The invention discloses a stress phosphorylation antibody aiming at a human Tudor-SN protein T103 site and a preparation method thereof. The preparation method adopts a multifunctional human Tudor-SN protein as a research object and comprises the following steps of determining if threonine at a 103 site of a human Tudor-SN protein under external environment oxidation stress is subjected to phosphorylation modification by near-infrared double-color laser imaging and mass spectrometry, synthesizing a T103 phosphorylation site-containing semiantigen polypeptide according to the secondary structure prediction result, coupling the T103 phosphorylation site-containing semiantigen polypeptide and a carrier protein (KLH) into a complete antigen, carrying out immunization on SPF-level New Zealand white rabbit by the complete antigen combined with an adjuvant four times and collecting, purifying and identifying a T103 specific stress phosphorylation polyclonal antibody. In practical application, Tudor-SN protein epigenetic phosphorylation modification in different stress environments can be detected, the effect mechanism of the Tudor-SN protein epigenetic phosphorylation modification in cell stress tumor propagation and migration can be discussed and a latent action target point for clinical tumor disease diagnosis and treatment is provided.

The present invention provides methods for identifying a molecule that provides or enhances a sweet taste in the mouth and compositions containing such molecules. The methods involve determining the effect of a variety of known or new compounds on expression or functional activity of a glucose-transporter protein of the activity of an ATP-gated K+ channel (K_ATP) in a mammalian oral cell, taste cell, or heterologous cell that expresses the protein or channel.