Autoimmune disease is a condition in which the body’s immune system attacks its own healthy cells and tissues. Normally the immune system protects the body from harmful infection and foreign substances. It also maintain immune tolerance, which helps to stop the immune reaction against self body cells. In autoimmune disease, this self-tolerance is broken. The … Read more
Coomb’s test is a serological blood test which is used to detect antibodies or complement proteins attached with red blood cells (RBCs) or present freely in serum. It is also called antiglobulin test.Coomb’s test is a serological blood test which is used to detect antibodies or complement proteins present on the surface of red blood … Read more
Venereal Disease Research Laboratory (VDRL) test is a rapid and simple test used for screening of syphilis. It is caused by Treponema pallidum. This test is non-treponemal test because it does not detect the organism directly. It detects reagin antibodies which are produced in the body against lipoidal material. These antibodies are mainly IgG and … Read more
Antigen Processing and Presentation is a process by which antigen proteins are broken into small peptides and shown on cell surface with MHC molecules. These peptide-MHC complexes are recognized by T cells. It helps the immune system to detect infected cells, foreign antigen and abnormal cells. Antigen processing and presentation is a continuous immune surveillance … Read more
Superantigens (SAgs) are a special type of powerful toxins. These are produced by some bacterial and viral pathogens. It causes very strong and uncontrolled activation of immune system. The superantigens are different from normal antigens. Normal antigens are taken inside the antigen-presenting cells and broken into small pieces. But SAgs act as intact protein and … Read more
T-dependent antigens are the antigens which need the help of CD4+ helper T cells for complete activation of B cells. These antigens are mostly soluble or particulate proteins. They produce strong and long lasting immune response. When B cell comes in contact with T-dependent antigen, the antigen binds with B cell receptor (BCR). Then the … Read more
Precipitation Reaction is a reaction in which two soluble substances react together in a solution and form an insoluble solid substance. This insoluble solid substance is called precipitate. In chemical reaction, it occurs when the concentration of dissolved ions becomes more than their solubility limit. This limit is controlled by solubility product constant (Ksp). When … Read more
Immunity is the ability of the body to resist and protect itself from disease causing organisms. It acts against foreign substances like bacteria, viruses, toxins and other antigens. Immunity is the ability of the body to protect itself from infectious diseases and harmful foreign substances. It helps the body to recognize and destroy pathogens like … Read more
The organs of immune system are the organs and tissues which are involved in the defence of body. These organs work together to destroy or neutralize the pathogens. Pathogens may otherwise cause disease in the body. The organs of immune system are generally divided into three categories. These are primary lymphoid organs, secondary lymphoid organs … Read more
Cells of immune system are the protective cells of the body. These cells are concerned with defence against microorganisms, foreign particles, toxins and abnormal cells of own body. Most of these cells are formed in the bone marrow from hematopoietic stem cells. The hematopoietic stem cell gives rise to different blood cells. In immune system, … Read more
