Fluorescently labeled A protein FITC-SPA detection method

SPA is a major component on the cell wall of most Staphylococcus aureus. It can bind to Fc fragments of IgG from many normal mammals without affecting the immune activity of the antibody molecule. It can still react with the antigen. Fluorescent pigments can be labeled to make specific diagnostic preparations. In the conventional fluorescent antibody technique indirect staining method, a secondary antibody (i.e., an anti-globulin antibody) must be used, but due to the different types of animals, it is necessary to use secondary antibodies against various animals (such as rabbit anti-pigulin antibodies, Rabbit anti-globulin antibodies, etc.) and fluorescent antibodies against various animal globulins, which are not only complicated to operate, but also prone to generic reactions. SPA can bind to Fc fragments of IgG from a variety of mammals. Therefore, SPA can be used to replace the second antibody, which is not restricted by the animal species of the first antibody. At the same time, the preparation of SPA fluorescent reagent is simple, easy to purify and highly stable. When using it to detect viral antigens, virus-infected cells cultured on flying slides were gently washed twice with PBS, and then covered with labeled SPA fluorescent reagent, set at 4 ° C for 10 to 30 minutes, washed twice with PBS, and then slided. Place it on a glass slide and observe the result under a fluorescence microscope.