Antibodies are proteins produced by the immune system that protect the body from foreign substances, such as bacteria, viruses, fungi, and toxins. They recognize and bind to these substances, known as antigens, in order to eliminate them from the body. Antibodies are produced by B cells, which are specialized white blood cells, and are located in various areas of the body, including the skin, lungs, tears, saliva, and breast milk. There are five predominant types of antibodies produced, each specialized to execute certain functions. Antibodies can also be produced in a lab and used to treat certain health problems, such as cancer and heart disease.

Key points about antibodies include:

• Antigen vs. Antibody: An antigen is a foreign substance that enters the body, while an antibody is a protein produced by the immune system to attack and fight off these antigens.
• How Antibodies Fight Off Antigens: When an antigen comes into contact with a B cell, it causes the B cell to divide and clone. These cloned B cells, or plasma cells, release millions of antibodies into the bloodstream and lymph system. Antibodies attack antigens by binding to them, which can neutralize the poison or render invading microbes immobile or prevent them from penetrating body cells.
• Monoclonal Antibodies: These are lab-made antibodies that are used to treat certain health problems, such as cancer and heart disease.
• Clinical Applications of Antibodies: Antibodies have a plethora of clinical applications, including their use in combating autoimmune conditions and cancer, conferring passive immunity, and their diagnostic applications.

Each type of antibody is unique and defends the body against one specific type of antigen. The structure of an antibody consists of two light chains and two heavy chains, and at the very tip of the antibody is a hypervariable region, which allows the antibody to make different types of antibodies that will respond to all of the antigens that will assault the body.