In daily work serum immunoglobulin three, mainly refers to immunoglobulin IgA, IgG and IgM, the test of these three items can reflect the body’s humoral immune function. Serum immunoglobulin refers to proteins with antibody activity in human blood and tissues, serum immunoglobulin is mainly divided into five categories, IgA, IgG, IgM, IgE and IgD. When bacteria and viruses invade the organism, immunoglobulin is able to effectively resist bacterial and viral invasion. It is anti-bacterial, anti-viral, and enhances the phagocytosis of phagocytes, and with the assistance of complement, it effectively destroys and removes microorganisms invading the organism and protects the organism effectively.