BIONEXTS EDUCATION

  INTRODUCTION In immunology, an antigen (Ag) is any substance that can bind to a specific antibody or T-cell receptor triggering an immune response.This signifies that your immune system does not recognize the substance and is fighting it off by creating antibodies. LEARNING OBJECTIVES Understand what an Antigen is and its role in the immune system. Identify Types of Antigens: Learn about the different types of antigens, including auto-antigens, hetero antigens, and alloantigens. Antibody-Antigen Binding: Learn the mechanisms of antibody-antigen binding and specificity. ANTIGENS AND THEIR CHARACTERISTICS An antigen is a substance that triggers an immune response, leading to the production of antibodies by lymphocytes. Recognition : Antigens are recognized by antigen receptors, including antibodies and T-cell receptors. They can encompass proteins, peptides, polysaccharides, lipids, or nucleic acids found on various entities like cancer cells, parasites, fungi, viruses, and bac...

Introduction Antibodies, also known as Immunoglobulin are glycoproteins produced by the immune system to protect our body from pathogenic infections. It is a large Y-shaped protein produced by the immune system in response to the presence of foreign substances in the body, such as pathogens (e.g., bacteria, viruses), toxins, or other antigens. Antibodies are a crucial component of the adaptive immune system and play a central role in defending the body against infections and other threats. The primary function of antibodies is to recognize and bind to specific antigens, which are molecules or structures on the surface of foreign invaders. Each antibody is highly specialized to recognize a particular antigen, and the body can produce a vast array of different antibodies to combat various pathogens. Function of Antibodies The first function is to recognize and bind to the foreign material(antigen) - antigenic determinants and thereby, Neutralization : Antibody binds to antigens on the su...

  INTRODUCTION Radioimmunoassay (RIA) stands as a remarkably sensitive laboratory method employed to quantify specific molecules, such as cytokines, within biological specimens. Principle of RIA : RIA hinges on the competition between a radioactively labeled antigen (of known quantity) and an unlabeled antigen (found in the sample) for binding to a limited number of specific antibodies. Radioactive Labeling : A measured amount of the cytokine of interest gets tagged with a radioactive isotope, like I-125. This labeled cytokine serves as a tracer in the assay. Antibody Preparation : Polyclonal or monoclonal antibodies that specifically target the cytokine are generated. These antibodies exhibit a high affinity and specificity for the target cytokine. Sample Preparation : The sample (e.g., serum or plasma), containing an unknown concentration of the cytokine, is introduced into the assay tube. Addition of Labeled Antigen : A known quantity of the radioactively labeled cytokine is ...