Antigen and Antibody 

Antigen and antibody are both involve in our immunology system and correlate each other through the process of antibody and antigen reactions. Antigen usually provokes immune response to produce antibody which then acts to fight and destroy antigen. Antigen and antibody interactions are reflected through the reactions of lock and key concept where specified antibody will attached to particular antigen to inactivate them with antibodies' heavy and light chains. They are attached through nature with substance called hydrogen bonds, electrostatic bonds, hydrophobic bonds and Van der Wall forces.


Antigen is a foreign particle in our body that prompt immune response made up of proteins and polysaccharides. Antigen is also known as antibody generator that catalyzes the production of antibody which available is two types; self antigen and non self antigen. Self antigen does not prompt from the immune system but usually leads to immune response such as autoimmune diseases. Each antigen has antigenic determinant called ‘epitope' to lock in the antibody to the compatibility area. Antigen is varied by different type called immunogen, tolerogen as well as allergen. Immunogen is a substance that prompts an immune reaction in the body according to the foreignness of the host, molecular size, heterogeneity and chemical composition while tolerogen is an antigen that provokes only an explicit immune insensitivity as a result of its molecular form. However, tolerogen can transform itself to an immunogen if the molecular form is modified.


An antibody consists of protein molecule which exists in the blood and secretions to inactivate or destroy foreign particles in body system called antigens. Antibody is also known as immunoglobulins has a Y shaped protein particles, produced from B cells as a response to the immune system which attached to the epitope of antigens. Like antigens, there are different types of antibody in forms of heavy and light chains, location, functions, trans placental transportation, produced to destroy different types of antigen as each antibody only attacks different antigens uniquely.

What is the difference between Antibody and Antigen?

  • Both antibody and antigen play an important role for immune system.
  • Antigen and antibody involves in autoimmune diseases where antigen and antibody are dependant to each other to generate autoimmunization to the body.
  • Antibody and antigen is differing by their types where antigen can be cells but antibody is never a cell.
  • Both antibody and antigen contains protein and known as a type of microscopic particles. However, antigens consist of proteins pregnancy with IUD and polysaccharides whilst antibodies contain only proteins.
  • Unique antigens are complementary to each type of antibodies where antigens act as the key to lock antibodies. Antibodies are attached to the antigens accordingly to destroy and inactivate antigens.
  • Antigens consists of two categories, non self and non self where at the same time antibodies are categorized in five types based on the protein constructions.

Both antigen and antibody can be viewed in different aspects and perspective as investigations are actively been carried out to study the reactions between antigen and antibody as well as to diagnose certain diseases, rigorousness of the circumstance and cures for certain diseases.