44 results about "Streptolydigin" patented technology

The invention relates to a detection kit for interleukin 6. The detection kit comprises two specific monoclonal antibodies of the interleukin 6; one monoclonal antibody covering a perforated plate, the other monoclonal antibody labeled by biotin and the interleukin 6 of a sample to be detected form a sandwich compound structure of covering antibody-antigen-biotin labeled antibody; the biotin labeled on the antibody combines with streptavidin labeled by HRP, and then the HRP reacts with a substrate to generate a signal which is used for conducting quantitative analysis on the interleukin 6. The detection kit can quantitatively detect the content of the interleukin 6 in the sample rapidly and sensitively.

The invention relates to a nucleic acid detection method combining RNA amplification with a hybrid capture method. The nucleic acid detection method includes the following steps of extracting nucleic acid from a sample or splitting the sample to release the nucleic acid to be detected, conducting transcription and amplification on the nucleic acid to be detected to obtain an RNA product, adding the obtained RNA product together with a DNA probe marked with biotins to a solid phase so that hybridization can be conducted, forming a DNA / RNA heterozygote through hybridization, coating the solid phase with specific antibodies for recognizing the heterozygote or avidin or streptavidin, capturing the heterozygote through the solid phase, and adding avidin or streptavidin or antibodies for recognizing the DNA / RNA heterozygote to the solid phase to achieve obtaining of a nucleic acid signal, wherein the avidin or the streptavidin or the antibodies for recognizing the DNA / RNA heterozygote are marked with enzymes with the secondary amplification capacity. According to the nucleic acid detection method, the inherent pollution problem of the PCR is avoided, RNA molecules can be directly detected, inverse transcription and pre-dissociation of RNA do not need to be conducted, and the operation steps are greatly simplified.

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 discloses a preparation method of developing Phaseolus vulgaris SSR primers by magnetic bead enrichment. The method comprises the following steps of: (1) digesting Phaseolus vulgaris genome DNA with Msel, and establishing a library by AFLP; (2) hybridizing the genome PCR library with a biotin-labeled repetitive sequence probe; (3) adding the hybridization mixed liquid into streptavidin-coated magnetic beads; (4) amplifying micro-satellite DNA fragments by PCR using eluent-purified micro-satellite DNA as DNA template; (5) linking the purified PCR amplification product on a T vector for cloning to obtain a DNA sequence with inserted fragments; and (6) repeating on the two sides of the core area to design primers, and screening primers to obtain effective microsatellite loci. The method is simple and feasible, increases efficiency of the primers, screens 20 pairs of effective primers from 48 pairs of primers, and provides guarantee for large-batch development of SSR primers.

The invention relates to phycocyanin beta subunits fluorescent protein combined with phycoerythrobilin PEB, fusion protein formed by phycocyanin 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 beta subunit conserved cysteine residue can be not only combined with phycocyanobilin PCB by a thioether bond, but the fact that the phycocyanin 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, the spectroscopy of the protein is completely different from that of the phycocyanin 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.

The invention discloses a method for preparing an ELISA enzyme-labelled antigen through utilizing an avidin binding peptide and avidin combining principle. The enzyme-labelled antigen is formed by recombining, antigenically fusing and mixing an enzyme-labelled streptavidin (one type of avidins) with a streptavidin binding peptide (SBP). The method comprises steps of: utilizing the principle that the enzyme-labelled streptavidin and biotin can be specifically bound with each other, and adopting a genetic engineering method to structure the streptavidin binding peptide (SBP) with a simulated biotin structure with antigenic protein molecules so as to form a fusing protein; and binding the SBP in the fusing protein with the enzyme-labelled streptavidin through affinity, and thus forming a novel enzyme-labelled antigen with antigenic activity and enzymatic activity. The method does not need special chemical groups as a coupling target position and has wide applicability; and moreover, the antigenic molecules are not directly labeled, the influence on an antigenic structure is reduced, and the steric hindrance of a labeled object to antigen-antibody reaction is decreased, so that the detection sensitivity is improved.

The invention relates to phycocyanin alpha subunits fluorescent protein combined with phycocyanobilin PCB and fusion protein formed by phycocyanin alpha subunits fluorescent protein and streptavidin, the sequences include sequence 1 and sequence 2; furthermore, the invention discloses a method of the fluorescent protein fused with streptavidin for fluorescent immunological detection directly; phycocyanin alpha subunit conserved cysteine residue can be combined with phycocyanobilin PCB by a thioether bond, and the alpha subunit of the fluorescent phycocyanin can be obtained by utilizing escherichia coli through genetic engineering, the spectroscopy of the protein is completely different from that of natural phycocyanin; 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.

The invention discloses a metagenome extraction method for specifically reducing or removing a host genomic DNA based on a CRISPR-Cas system composition. The invention aims to provide a technique forreducing a host genomic DNA background in metagenome sequencing and improving effective sequencing data of other microorganisms. The CRSIPR-Cas system in the method comprises a plurality of crRNA or crRNA / tracrRNA derivatives, as well as a biotin-labeled Cas protein or variant protein with endonuclease activity deficiency. The sequence of the crRNA or crRNA / tracrRNA derivatives is complemented with a repetitive sequence Alu element region (target sequence) in the host genomic DNA, so that the binding of the Cas protein or the variant thereof with endonuclease activity deficiency is guided to be bonded on the host genomic DNA, the CRISPR-Cas system and the bonded host DNA are captured by adding magnetic beads coated with streptavidin, and thus the concentration of the host genomic DNA in asample solution is reduced and the abundance of nucleic acids of other non-host genomic DNA is improved.

The invention relates to a non-diagnosis-targeted HIV antibody immunity detecting method and a kit. The method comprises the following steps: specifically capturing and detecting an HIV antibody in a sample by using an HIV antigen, then adding a biotinylated secondary antibody, and incubating to form an antigen-antibody-biotinylated secondary antibody compound; adding a biotinylation primer Biotin-I in the presence of streptavidin, incubating to combine the compound with the Biotin-I, and then adding biotinylated hairpin chain Biotin-H1 and hairpin chain H2 to carry out hybridization reaction; adding avidin marked horseradish peroxidase, catalyzing a substrate solution to develop color, and carrying out quantitative detection on the HIV antibody by determining absorbance. HCR is guided into ELISA, signals are amplified by the HCR, ultra-sensitive detection of the HIV antibody is realized, and lower limit of detection is as low as 9.5 pg / mL, and is higher than that of the traditional ELISA by about 2 orders of magnitude.

Provided are determining methods of human papillomavirus (HPV) genotypes with a high sensitivity. The method includes performing two-step PCRs on an HPV L1 gene in a sample to be analyzed as a biotin-labeled, single-stranded L1 gene, performing a hybridization reaction on the biotin-labeled, single-stranded L1 gene with a HPV genotype detection probe, reacting the hybridization reaction product with fluorescent substance combined with streptavidine, and measuring a fluorescent substance level to identify the HPV genotype. The detection method has high sensitivity enough to detect an extremely small amount of HPV in the sample. In addition, the high specificity exhibited by the detection method enables accurate diagnosis specific to HPV type.

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.

The present invention discloses process of fast screening lydistreptomycete mutant for producing lydistreptin. The process includes the following steps: compounding culture medium; seed culture and fermentation; preparing sample; Fourier transform infrared spectral analysis; data processing; and main component analysis and artificial neural network analysis on the infrared data. The process can screen out lydistreptomycete mutant for producing lydistreptin fast and raise mutation efficiency.

The invention relates to a molecular design phycoerythrocyanin beta subunit fluorescent protein combining phycoerythrobilin, fusion protein formed by the phycoerythrocyanin 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 phycoerythrocyanin 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 phycoerythrocyanin can be obtained. The spectrum property of the phycoerythrocyanin is completely different from that of the phycoerythrocyanin 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 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 an RNA (Ribonucleic Acid) antisense purification method. The RNA antisense purification method comprises the following steps: S1, cross linking and pyrolysis of cells and digestion of genome DNA (Deoxyribonucleic Acid), thus obtaining an RNA sample; S2, preparation of a probe group solution; S3, pre-treatment of magnetic beads; S4, preparation of a probe group-magnetic bead compound; S5, antisense purification; S6, elution of RNA; S7, purification of the RNA. According to the RNA antisense purification method disclosed by the invention, the magnetic beads are sealed by using BSA (Bull Serum Albumin) and random oligonucleotide primer in advance, so that non-specific adsorption of the magnetic beads is reduced; the magnetic beads are in incubation with probes at first and then is in incubation with the RNA after residual probes are removed, non-specific combination of streptavidin with protein, nucleic acid and the like is sealed by excessive probes, the detection specificity is increased, and the sensitivity is high; multiple washing under a gradient temperature is carried out after hybridization, so that the magnetic beads are enabled to be fully combined with the probes and to be combined with a target RNA, and the hybridization efficiency is increased.

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 phycocyanin and phycoerythrin alpha subunits fluorescent protein combined with phycoerythrobilin PEB and fusion protein formed by phycocyanin and phycoerythrin alpha 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; phycocyanin and phycoerythrin alpha subunit conserved cysteine residue is combined with phycoviolobilin PVB by a thioether bond, the fact that the phycocyanin and phycoerythrin alpha 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 alpha subunits fluorescent protein combined with PEB, 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.

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 nondiagnostic HCV (hepatitis c virus) antibody immunodetection method and a kit. The method comprises steps as follows: an HCV antigen specifically captures an HCV antibody in a detection sample, a biotin-labeled second antibody is added, and an antigen-antibody-biotin-labeled second antibody compound is formed after incubation; in the presence of streptavidin, a biotin primer Biotin-I is added, incubation is performed, so that the compound and the Biotin-I are bound, and then, a hair grip chain H1 and a hairpin chain Biotin-H2 are added for a hybridization reaction; avidin-labeled horseradish peroxidase is added, a substrate solution is catalyzed to develop, and quantitative detection of the HCV antibody is performed by measuring the absorbance. ELISA (enzyme-linked immuno sorbent assay) is introduced into an HCR (hybridization chain reaction), HCR is used for signal amplification, ultra-sensitive detection of the HCV antibody is realized, and the lower limit of detection is lower than 10 pg / mL and is improved by at least two orders of magnitude as compared with conventional ELISA.

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 discloses a streptolydigin output improving method, which comprises the following steps: (1) preparing of a culture medium and an amino acid mother liquid; (2) seed culture; (3) adding of proline for fermentation, to be more specific, centrifuging two stage seeds to obtain mycelium, using a fermentation medium for resuspending the mycelium, inoculating the mycelium into a fermentation tank provided with the fermentation medium according to the inoculum density of 5% to 30% in volume ratio, then adding a proline mother liquid for 80-150h of fermentation under the conditions of the speed of agitator of 200-600rpm, the ventilation volume of 1-3vvm and the pH of 6-8 to obtain a fermentation broth; and (4) determination of streptolydigin content. According to the streptolydigin output improving method, by adding of the proline in the fermentation process, the streptolydigin output in the fermentation process can be greatly improved, and a foundation is laid for the development and utilization of streptolydigin.

The invention discloses a biosensor for synchronously detecting amyloid polypeptide monomers and aggregate and a construction method and application thereof. The biosensor comprises an amyloid polypeptide aggregate aptamer containing a methylene blue probe, and antibody modified DNA. The construction method of the biosensor includes the steps that sulfydryl modified cDNA is fixed to an electrode through chemical bonding, after short chain DNA, the amyloid polypeptide aggregate aptamer containing the methylene blue probe and DNA connected with biotins are sequentially modified on the cNDA in a complementary mode, the object further reacts with streptavidin and an antibody connected with biotins, and then the biosensor is obtained. The construction method of the biosensor is simple, and the biosensor can be used for respectively or simultaneously detecting amyloid polypeptide monomers and aggregate, and has the advantages of being simpler in detection, low in detection limit, high in sensitivity and high in specificity.

The invention discloses a method for efficiently and quickly screening HIV P24 antigen nucleic acid aptamer. The method includes that subduction index enriched ligand system evolution (SELEX) technology and qPCR technology are utilized, streptavidin is adopted to prepare single-stranded DNA, TPBS is used to wash away nonspecific single-stranded DNA, comerical carboxylated agar magnetic beads are used as a separation medium for selex screening, and the HIV P24 antigen nucleic acid aptamer is obtained by screening from a random oligonucleotide library, so that screening efficiency is improved. Therefore, the method can serve as early detection technology, a method which is high in sensitivity, low in cost and simple and convenient to operate is provided for clinical detection, a new specific carrier is provided for tumor treatment, and a foundation is laid for screening other single target protein and tumor serum marker nucleic acid aptamer. The method is high in screening efficiency, short in period and low in cost.

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.

The invention relates to a molecular design phycoerythrocyanin beta subunit fluorescent protein combining phycocyanobilin (PCB), fusion protein formed by the phycoerythrocyanin 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 phycoerythrocyanin beta subunit can be combined with the phycocyanobilin (PCB), and is prepared into beta subunit of fluorescent phycoerythrocyanin by escherichia coli of genetic engineering. The spectrum property of the phycoerythrocyanin is completely different from that of the natural phycoerythrocyanin, 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 phycocyanin and phycoerythrin beta subunits fluorescent protein combined with phycocyanobilin PCB, 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 combined with phycocyanobilin PCB by a thioether bond, and the beta subunit of the fluorescent phycocyanin and phycoerythrin can be obtained by utilizing escherichia coli through genetic engineering, the spectroscopy of the protein is completely different from that of natural phycocyanin and phycoerythrin; 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.

The invention relates to allophycocyanin subunits fluorescent protein combined with phycoerythrobilin PEB 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 phycoerythrobilin PEB 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.