44 results about "Streptolydigin" patented technology

The invention provides a nucleic acid aptamer-based escherichia coli O157:H7 colloidal gold test strip. The nucleic acid aptamer-based escherichia coli O157:H7 colloidal gold test strip comprises a sample pad, a colloidal gold combined pad, a nitrocellulose membrane immobilized with streptavidin, and an absorbent pad; the nitrocellulose membrane is provided with a detection line and a quality control line; the sample pad, the colloidal gold combined pad, the nitrocellulose membrane, and the absorbent pad are glued onto a plastic liner board successively; colloidal gold labeled nucleic acid aptamer is arranged on the colloidal gold combined pad; a capture probe is immobilized on the detection line; and a quality control probe is immobilized on the quality control line. The invention also provides a method used for detecting escherichia coli O157:H7 with the nucleic acid aptamer-based escherichia coli O157:H7 colloidal gold test strip. According to the nucleic acid aptamer-based escherichia coli O157:H7 colloidal gold test strip, the escherichia coli O157:H7 outer membrane protein high specificity aptamer is taken as a recognition element of test strip instead of antibodies, so that problems of immunochromatographic test strip containing antibodies, such as high cost, large batch difference, induced cross reaction, and low sensitivity, are solved, and high-efficiency rapid detection of escherichia coli is realized.

The invention relates to the technical field of biology, and particularly to a kit for determining a concentration of an apolipoprotein C-III and a preparation method. The invention adopts the following technical scheme: the kit for determining the concentration of the apolipoprotein C-III is characterized by comprising a reagent R1 and a reagent R2; biotin and streptavidin are added into the reagent R2; the ratio of the biotin to the apolipoprotein C-III antibody is 2:1, and the ratio of the streptavidin to the biotin-apolipoprotein C-III antibody is 1:1. The kit for determining the concentration of the apolipoprotein C-III and the preparation method disclosed by the invention have the advantages that a cascaded amplification reaction is adopted in which the apolipoprotein C-III antibodyis connected with the biotin at the radio of 1:2, and is mixed and reacted with the streptavidin at the radio of 1:1, thereby significantly improving the repeatability and sensitivity, and the linearrange can reach 2-100 mg / L.

A detection reagent strip utilizing a recombinant fluorescent phycobiliprotein subunit comprises a non-fluorescence bottom plate, first non-fluorescence filter paper, a detection protein binding membrane, a fluorescent sample pad and second non-fluorescence filter paper, wherein a detection line and a control line are arranged on the detection protein binding membrane; a detection antibody is marked on the detection line; a control antibody is marked on the control line; the fluorescent sample pad comprises a glass fiber membrane and a mixture of a streptavidin blended phycobiliprotein subunit and a biotinylated antibody; the mixture covers the glass fiber membrane. In addition, the invention further provides a preparation method of the detection reagent strip utilizing the recombinant fluorescent phycobiliprotein subunit. The detection reagent strip utilizing the recombinant fluorescent phycobiliprotein subunit can perform qualitative and quantitative detection on antigens or antibodies of diseases such as tumor and microbial infection, and the recombinant fluorescent phycobiliprotein subunit used by the reagent strip is environmentally friendly. The preparation method is low in purification preparation cost and environmentally friendly.

The invention provides a detection method of hepatitis A viral antigen. The method comprises the steps: long arm biotin is adopted to mark HAV-IgG, horse radish peroxidase is adopted to mark streptavidin to be used as an amplifying system, when the hepatitis A viral antigen is detected, as the long arm biotin has longer space arm than common biotin, the sterically hindered can be reduced, and a plurality of biotin molecules can be simultaneously combined with an avidin compound; moreover, as water-soluble biotin, the long arm biotin marks the hepatitis A viral antigen directly, can reduce the steps of the immunological detection and the detection time, namely the total detection time can be reduced to 3.5 hours from usual 2 days, the background can be reduced through reducing cross reaction, and the detection sensitivity can be improved; in addition, as the streptavidin marked by the horse radish peroxidase is different from avidin, the molecular weight is about 60000, carbohydrate is not included, and the nonspecific binding is lower than the avidin, therefore the method has the effects of improving sensibility and specificity.

The invention relates to a molecular design phycocyanin beta subunit fluorescent protein combining phycocyanobilin, fusion protein formed by the phycocyanin beta subunit fluorescent protein and streptavidin, and mutant thereof, having the sequences 1, 2, 3 and 4. The invention also discloses a method for directly using the fluorescent protein fused with the streptavidin for fluorescence immunoassay; and due to thioether bond, 153th cysteine residue conserved by phycocyanin beta subunit can be combined with the phycocyanobilin (PCB), and is prepared into beta subunit of fluorescent phycocyanin by escherichia coli of genetic engineering. The spectrum property of the phycocyanin is completely different from that of the natural phycocyanin, and is convenient for purification due to being provided with His-tag label. Furthermore, the dissolubility can be improved, the fusion protein can be formed by the phycoerythrocyanin beta subunit fluorescent protein and the streptavidin, the fluorescent protein can be directly used for fluorescence immunoassay, and the invention is beneficial to the application in various fields.

The invention relates to a molecular design phycocyanin beta subunit fluorescent protein combining phycoerythrobilin, fusion protein formed by the phycocyanin beta subunit fluorescent protein and streptavidin, and mutant thereof, having the sequences 1, 2, 3 and 4. The invention also discloses a method for directly using the fluorescent protein fused with the streptavidin for fluorescence immunoassay; and due to thioether bond, 153th cysteine residue conserved by phycocyanin beta subunit not only can be combined with phycocyanobilin (PCB), but also can be combined with the phycoerythrobilin (PEB) through genetic engineering, so that a novel fluorescent phycocyanin can be obtained. The spectrum property of the phycocyanin is completely different from that of the phycocyanin beta subunit fluorescent protein combined with the PCB, has higher fluorescence efficiency, and is convenient for purification due to being provided with His-tag label. Furthermore, the dissolubility can be improved, the fusion protein can be formed by the phycocyanin beta subunit fluorescent protein and the streptavidin, the fluorescent protein can be directly used for fluorescence immunoassay, and the invention is beneficial to the application in various fields.

The invention relates to allophycocyanin subunits fluorescent protein combined with phycocyanobilin PCB and fusion protein formed by allophycocyanin subunits fluorescent protein and streptavidin, the sequences are from sequence 1 to sequence 10; furthermore, the invention discloses a method of the fluorescent protein fused with streptavidin for fluorescent immunological detection directly; allophycocyanin subunit conserved cysteine residue is combined with the phycocyanobilin PCB by a thioether bond, and the subunit of the fluorescent allophycocyanin can be obtained by utilizing escherichia coli through genetic engineering, the spectroscopy of the protein carries His-tag label, therefore, purification is not only convenient, but also the dissolubility of the protein can be improved; the protein is combined with the streptavidin to form the fusion protein for fluorescent immunological detection directly, thereby being beneficial to the application of the protein in all kinds of the field.

The invention relates to phycocyanin and phycoerythrin beta subunits fluorescent protein combined with phycoerythrobilin PEB, fusion protein formed by phycocyanin and phycoerythrin beta subunits fluorescent protein and streptavidin and a mutant thereof, the sequences include sequence 1, sequence 2, sequence 3 and sequence 4; furthermore, the invention discloses a method of the fluorescent protein fused with streptavidin for fluorescent immunological detection directly; phycocyanin and phycoerythrin beta subunit conserved cysteine residue can be not only combined with phycocyanobilin PCB by a thioether bond, but the fact that the phycocyanin and phycoerythrin beta subunit conserved cysteine residue can be combined with the phycoerythrobilin PEB by the thioether bond through the genetic engineering can be realized, so as to obtain the novel fluorescent phycocyanin and phycoerythrin, the spectroscopy of the protein is completely different from that of the phycocyanin and phycoerythrin beta subunits fluorescent protein combined with PCB, and the protein has high fluorescence efficiency; in addition, as the protein carries His-tag label, purification is not only convenient, but also the dissolubility of the protein can be improved; the protein is combined with the streptavidin to form the fusion protein for fluorescent immunological detection directly, thereby being beneficial to the application of the protein in all kinds of the field.