72results about How to "Avoid non-specific adsorption" patented technology

The invention discloses a preparation method and application of fusion protein with broad spectrum adsorption capacity to antibodies. The method includes the steps: obtaining a protein A and a protein G immune globulin binding zone gene by means of T vector connection and double digestion by the genetic engineering means and via PCR (polymerase chain reaction) amplification; then connecting onto an expression vector pET-23a to form a recombinant plasmid, converting E.coli BL21(DE3), and obtaining a great number of thalli containing the fusion protein AG after inducible expression; and finally, performing ultrasonication, high-temperature heating, precipitation of DNA (deoxyribonucleic acid) and purification of weak anion exchange chromatography and affinity chromatography so that the fusion protein AG is obtained. The fusion protein has dual advantages of the protein A and the protein B and is wider in spectrum combination and low in nonspecific adsorption of non-immune globulin substances of albumin in serum and the like. The fusion protein serving as a ligand is connected to a solid-phase vector matrix to be prepared into adsorbent so that the shortcoming of poor IgG3 binding force of protein A adsorbent is overcome, and can be applied to the fields of antibody purification, blood purification and the like.

The invention discloses an ELISA detection method based on nano-enzyme with catalase activity. The ELISA detection method is applicable to a double antibody sandwich method or a dual antigen sandwich method. The method comprises the following steps: firstly modifying detection antibody / detection antigen on a gold nanoparticle; performing ELISA detection and forming a compound of capturing antibody / capturing antigen, to-be-detected antibody / to-be-detected antigen, detection antibody / detection antigen and gold nanoparticle; performing silver platinum dyeing and wrapping the gold nanoparticle surface with silver shell layer and platinum shell layer, thereby acquiring the nano-enzyme Au@AgPt grain with catalase activity; and utilizing Au@AgPt grain to catalyze hydrogen peroxide decomposition for generating hydrogen in an airtight system, increasing the air pressure in the airtight system, detecting the air pressure change, namely, detecting and acquiring the volume of the to-be-detected antibody / to-be-detected antigen. A method of forming enzyme after modifying is applied to the ELISA detection method, so that the ELISA detection method has the advantages of simplicity and quickness, high stability, capability of effectively preventing the nano-enzyme particle catalytic activity caused by nonspecific adsorption and modification from decreasing and capability of supplying new platform to the environment monitoring and disease diagnosis.

The invention discloses magnetic red blood cell clusters for enriching circulating tumor cells based on a magnetic separation method, and belongs to the technical field of biological medicines. Red blood cells are combined with nanometer-grade magnetic microspheres to obtain a red blood cell cluster type biomimetic material, and polybrene is modified on the surfaces of the red blood cells, so thatelectrostatic repulsion originally existing between the red blood cells can be eliminated, and further, the red blood cells can be tightly covered on the surfaces of the microspheres in the total layer. The red blood cells pack the nanometer-grade magnetic microspheres to prevent non-specific adsorption of white blood cells on the surfaces of the microspheres, and besides, folic acid (FA) modified on the surfaces of the red blood cell clusters or an antibody specially recognized or combined with a CTCs surface biomarker can realize direct targeting on CTCs, and finally, in a magnetic separating manner, the white blood cells in blood samples of a clinical patient can be removed, so that high-purity CTCs can be efficiently obtained.

The invention relates to the technical field of immunological detection, specifically relates to a kit for quantitatively detecting anti-SS-A antibody IgG by utilizing magnetic particle chemiluminescence, a preparation method and a detection method thereof. The kit for quantitatively detecting anti-SS-A antibody IgG by utilizing magnetic particle chemiluminescence comprises an Anti-SS-A IgG calibration product, an Anti-SS-A IgG reagent 1#, an Anti-SS-A IgG reagent 2#, an Anti-SS-A IgG magnetic separation reagent, an Anti-SS-A IgG quality control material and a cleaning fluid. The invention also discloses the preparation method and the detection method for the kit. According to the detection method, on the basis of the traditional film strip immunization and enzyme linked immunosorbent assay, the sensitivity and the linearity range are increased by 3-5 orders of magnitudes and the quantitative detection is realized; the kit has the advantages of high sensitiveness, strong specificity, high accuracy, low cost, convenience in operation and objective judging result; the full-automatic chemiluminiscence immune analyzer is used for realizing the full-automatic use and has wide application prospect.

The invention discloses a blood platelet magnetizing and immunolabeling analysis method. The method comprises the following steps: uniformly mixing blood platelets and magnetic beads; magnetizing the blood platelets to obtain suspension; uniformly mixing, incubating and washing the magnetized blood platelets and a detected sample; adding a labeled second antibody and incubating to obtain mixed liquid; applying magnetic force to layer the mixed liquid; determining upper reaction liquid or determining after washing the magnetized blood platelets in the lower layer to obtain a result, namely performing double-phase complementary immune analysis. In the mode, the blood platelet magnetizing and immunolabeling analysis method provided by the invention is used for detecting blood platelet related antigen antibody and cross-matching of blood; the magnetic force is applied so that the magnetized blood platelet is washed without centrifuging; the method is easy and convenient to operate; by a labeled antibody adsorption test for directly determining the upper reaction liquid, the non-specific adsorption in an immunolabeling technology is overcome, the processes of closing and washing are reduced, and the time consumption is short. The method can detect a large number of samples and facilitates automation; the two detection results of the double phases can be verified mutually, so that the accuracy of the detection results is improved.

The invention relates to a production method of human antithrombin III. The production method comprises the following steps: removing cryoprecipitate from fresh frozen human plasma to obtain a plasma supernatant, and carrying out adsorption treatment on the plasma supernatant by using a DEAE Sephadex-A50 gel; precipitating impurity protein of the plasma supernatant, and deeply filtering plasma; carrying out Capto Heparin affinity chromatography; carrying out S / D virus inactivation and Capto Q ion exchange chromatography, and removing an S / D reagent; and filtering by virtue of a nanometer film to remove viruses, preparing, freeze-drying and dry-heating. The process is capable of preparing the antithrombin III by virtue of affinity chromatography with only one step. According to the production method disclosed by the invention, the recovery rate can reach above 40 percent, and the specific activity can reach 8-10 IU / mg.

The invention discloses an immunosorbent for removing inflammatory factors in blood and a preparation method thereof. Based on a variety of intermolecular interactions between the antigenic epitope ofinflammatory factors such as IL-6, TNF-alpha, IL-1 beta and IL-8 and corresponding receptors thereof, affinity ligand of small molecule polypeptide with 5-18 selective amino acids is designed througha computer-assisted drug design method. Specifically, with vinyl acetate-triallyl isocyanurate as a basic skeleton, a mixture of ethyl acetate and alkane as a pore-forming agent, and a synthetic resin with benzoyl peroxide as an initiator as a carrier, alcoholysis activation is carried out, and then the small molecule polypeptide is grafted to obtain the small-molecule ligand immunosorbent whichdoes not adsorb macromolecular proteins and the like. The immunosorbent is simple to prepare, has high adsorbing capacity, high selectivity, good biological and blood compatibility, and relatively lowcost, and provides a new therapeutic method for removing excessive pathogenic inflammatory factors in patients.

The invention provides a high-polymer material with cholic acid, a method for preparing the high-polymer material and liposome. The high-polymer material is shown as a formula I. Phospholipid and cholesterol are used as carriers for the liposome, the liposome is modified by the high-polymer material shown as the formula I, and medicines are entrapped in bi-molecular layers of the phospholipid. Thehigh-polymer material, the method and the liposome have the advantages that an active targeting effect and a passive targeting effect can be realized by the liposome; the method is simple and practical, amplification production can be facilitated, the high-polymer material and the liposome are high in targeting capacity for livers as shown in in-vivo experiments, and accordingly the high-polymermaterial, the method and the liposome have excellent application prospects.