Shandong has developed a new coronavirus detection kit for colloidal gold method and immunochromatography method
IgM mainly exists in the blood of organisms and plays a major role in preventing bacteremia. Therefore, the determination of IgM antibodies has high clinical diagnostic value for certain infectious diseases. IgM accounts for 5% to 10% of the total serum immunoglobulin, and the serum concentration is about 1 mg/ml. Monomer IgM is expressed on the surface of B cells in a membrane-bound form and constitutes a B cell antigen receptor. Igm is the earliest antibody that appears in the initial humoral immune response and is the forerunner of the body's anti-infection. IgM detected in the serum indicates the recent occurrence of infection and can be used for early diagnosis of infection.
Professor Wang Chuanxin of the Second Hospital of Shandong University, together with Shandong Normal University and Weifang Kanghua Biotechnology Co., Ltd. established a joint R&D team to develop a new coronavirus (2019-nCoV) IgM antibody detection kit (colloidal gold method and immunochromatographic method). Results will be available within 3 minutes at the fastest.
Colloidal Gold Method
Under the action of reducing agents such as white phosphorus, ascorbic acid, sodium citrate, tannic acid, chloroauric acid (HAuCl4) can polymerize into gold particles of a certain size, and become a stable colloidal state due to static electricity, forming a negative charge Hydrophobic glue solution of phosphate becomes a stable colloidal state due to static electricity, so it is called colloidal gold. Colloidal gold is also an ideal immunological marker in immunoelectron microscopy.
The basic principle of immune colloidal gold technology:
Colloidal gold is negatively charged in a weak alkaline environment and can form a firm bond with the positively charged groups of protein molecules. Since this bond is electrostatic, it does not affect the biological properties of the protein. In addition to binding to proteins, colloidal gold can also bind to many other biological macromolecules, such as SPA, PHA, ConA, etc. Coupled with the immune and biological properties of the conjugate, colloidal gold is widely used in immunology, histology, pathology and cell biology. The reduction method can be used to conveniently prepare colloidal gold particles of various sizes, that is, different colors, from chloroauric acid. This spherical particle has a strong adsorption function for protein, and can bind non-covalently with Staphylococcus A protein, immunoglobulin, toxin, glycoprotein, enzyme, antibiotic, hormone, bovine serum albumin polypeptide conjugate, etc. Therefore, it becomes a very useful tool in basic research and clinical experiments.
Commonly used immune colloidal gold detection technology:
1. Immunocolloidal gold microscope staining method
2. Immunogold electron microscope staining method
3. Use a microporous filter membrane (such as a membrane) as a carrier, first spot the antigen or antibody on the membrane, add the sample to be tested after sealing, and then use the colloidal gold-labeled antibody to detect the corresponding antigen or antibody.
4. Colloidal gold immunochromatography
Immunochromatography
It is a new type of immunoassay method that appeared in the early 1980s. It is a simple and rapid immunological detection technology established on the basis of immunofiltration. The specific antibody is first fixed on a certain zone of the nitrocellulose membrane. When one end of the dried nitrocellulose is immersed in the sample (urine or serum), the sample will move forward along the membrane due to capillary action. When moving to the area where the antibody is immobilized, the corresponding antigen in the sample specifically binds to the antibody. If the area is stained with immunogold or immunoenzyme, the area can show a certain color, thereby realizing specific immunodiagnosis.
