A monoclonal antibody-based specific double-antibody sandwich method for the detection of Salmonella in food

Abstract

The invention discloses a specific double antibody sandwich method for detecting salmonella in food based on a monoclonal antibody, and belongs to the field of immunoassay. The specific double antibody sandwich method comprises the following steps: immunizing a 7-week-old BALB / c mouse by using smooth salmonella typhimurium LPS-coupled bovine serum albumin according to a sodium periodate method, and carrying out immunization, fusion and screening to obtain 12 monoclonal antibodies for specifically identifying salmonella LPS; marking the 12 monoclonal antibodies with horseradish peroxidase HRP respectively, and pairing the 12 monoclonal antibodies with salmonella paratyphi bacteria; using 8G3 as a coated antibody and 8G3-HRP as a detection antibody to establish the salmonella detecting specific double antibody sandwich method, so that salmonella paratyphi with the LOD of 1000000 CFU / mL can be detected. The specific double antibody sandwich method has cross reactions with all salmonella bacteria, but does not have cross sections with E.coli, E.coli O157:H7, enterobacter sakazakii, staphylococcus aureus and listeria monocytogenes, so that an overall, reliable, fast and efficient analysis method is provided for detection of the salmonella in the food.

Description

technical field [0001] The invention relates to a double-antibody sandwich method for quantitatively detecting Salmonella in food, belonging to the field of immune analysis. Background technique [0002] Salmonella is a global foodborne pathogen. Biologically, Salmonella is a kind of Gram-negative bacteria with blunt ends, no spores, and generally no capsule. The main antigens are O antigen, H antigen, and Vi antigen. Animal foods such as poultry, eggs, and dairy products are easily contaminated with Salmonella. After the human body ingests food containing bacteria, it will cause acute gastroenteritis, typhoid fever, children with low immunity and even sepsis and other symptoms. [0003] There are more than 2,000 serotypes of Salmonella, and the common serotypes in clinical practice are mainly Salmonella enteritidis, Salmonella typhimurium, and Salmonella paratyphi A. The application of well-regulated production operations and management systems such as hazard analysis an...

AI Technical Summary

Problems solved by technology

However, the mixed immunization of LPS and Salmonella bacteria is mainly due to the O-specific side chain of the bacterial LPS (LPS is a thymus-independent antigen, and generally only induces humoral immunity alone), and the core polysaccharide of Salmonella is difficult to induce effective immunity due to steric hindrance. Therefore, the screened monoclonal antibody and the established sandwich ELISA have strong specificity and are only specific for the detection of Salmonella typhimurium, which cannot meet the specificity requirements for the detection of Salmonella in actual samples.

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