Difference Between Antigens and Antibodies (With Table)

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A person needs to have a healthy body, and it can only be possible if every organ and body part of the individual is working properly. The immunity of a person has a very important role in making sure the organs and other parts are healthy and work properly. In case an individual has a weak immune system, he won’t be able to survive a little disease or infection such as the common cold.

To study the working and functions of immune is called immunology, two most important terms in it are Antigens and Antibodies. Both of them are related to immune and hence are used interchangeably. Following are differences along with information about them.

Antigens vs Antibodies

The difference between antigens and antibodies is that both of them are responsible for different functions in the body with the immune system. Antibodies are responsible for protecting the body from antigens or any other harmful substance the might enter the body, there has protection as an effect on the body, whereas Antigens are a substance that makes sure the antibodies are activated by triggering them hence their effect on the body is to trigger the Antibodies in the body, this is hoe both of them are related. Both of them are also called by a different name. Immunogens is another name for antigens, while Immunoglobulins is another name for antibodies. Other differences between them are mentioned below.

Antigens are related to immunology, and they bind with the other antibodies. It is important for triggering the antibodies for protecting the body from any harmful substance. It is also called Immunogens and has a chemical composition of Lipids, Proteins, and Carbohydrates. Originally it was known as the originator of antibodies. There are types of antigens categorized on the basis of their origin and response to the immune system, but all of them have an origin outside the body (except one type).

Antibodies are molecules used for the identification of foreign substances it also used for neutralizing them. It recognizes the unique pathogen that leads to triggering it. It is also called Immunoglobulins. Its main function is to protect the body from foreign substances and boost the immune system. In the absence of it, there will be no substance in the body for protection. There are five types of antibodies.

Comparison Table Between Antigens and Antibodies

Parameters of ComparisonAntigensAntibodies
CorrelationTriggers the immune response.Produced in response to Antigens.
Chemical CompositionLipids, proteins, carbohydrates.Glycoproteins
FunctionsCause diseaseProtects body.
TypesExogenous, endogenous, autoantigens, etc. IgM, IgG, IgE, IgD, and IgA

What are Antigens?

Following are types of antigens:

On the basis of their Origin

  1. Exogenous Antigens: these are the antigens that are originally from the external environment, i.e., outside the body of the individual. Example of this kind of antigen is bacteria, fungi, virus, and parasites. Exogenous antigens can enter from ingestion, respiration, or through any wounds. 
  2. Endogenous Antigens: they are metabolic products of the microorganisms that live in the body. Therefore it is generated inside the body.
  3. Autoantigens: these are the self-made proteins and, due to any reason (environmental alteration), are attacked by their immune system, and this attack is responsible for causing autoimmune diseases.
  4. Tumour Antigens: these are antigens that live on tumor cells.
  5. Native Antigens: this type of antigen is not processed by native antigens.

On the basis of the Immune Response

  1. Immunogen: they are able to generate the response of the immune system of a person on their own. 
  2. Hapten: these are non-proteins, and they require having a carrier molecule to gain the response of the immune system.

What are Antibodies?

It is a glycoprotein and is produced by plasma cells present in the blood. They are produced in response to specific antigens that might cause disease or serious infection to the body. They are made up of two heavy and two light chains. And the complete molecule of antibodies is shaped like a Y. They have many shapes and sizes, but the most common is the Y-shaped proteins, which are known as IgG antibodies (immunoglobulin G).

They can be found easily in both of the following:

  1. Blood Circulation
  2. Lymphatic System

The main function of antibodies in the body of an individual is to protect him from antigens or any other foreign substance from entering the body. These substances are harmful and can make a person sick, and therefore, it is important for the immune system to be strong to survive this, and antibodies provide that protection to it. Therefore the absence of it foreign substances will keep on harming the body.

Main Differences Between Antigens and Antibodies

  1. Both of them are molecules, but they are of different types or have Chemical compositions. Antigens can be Lipids, Proteins, or Carbohydrates, whereas the Antibodies are always Glycoproteins.
  2. Both of them have a different effect on the body. Antigens are responsible for causing either a disease or an infection in the body, whereas Antibodies have the opposite effect of Antigens in the body. It is responsible for protecting the body in any one of the two ways, first immobilizing the antigens and secondly by lysing the pathogen.
  3. Both Antigens and Antibodies have specific binding sites. Antigens have epitopes as a region where the interaction of antigens takes place with antibodies, whereas in the case of Antibodies have paratopes as variable regions where they interact with the epitopes of antigens.
  4. Both of them have different origins. Antigens are not originated from the inside of the body, but in fact, their origin is on the outside of the body (except one), whereas the inside body of an individual is the original area of the Antibodies.
  5. They have different functions to perform related to the betterment of the immune system. Antigens have the function of triggering the function or formation of the antibodies, whereas the antibodies have the function of protecting the body of an individual.
  6. Both of them also have different synonyms. For Antigens, it is Immunogens, and for Antibodies, it is Immunoglobulins.
  7. There are three types of antigens Exogenous Antigen, Endogenous Antigen, and Autoantigens, etc., while there are five types of antibodies IgM, IgG, IgE, IgD, and IgA.


Therefore, there should not be any confusion between Antigens and Antibodies after all the information mentioned above. Both of them are similar as they are involved in triggering the immune system, both of them are molecules, and both of them are involved in demolishing foreign substances. Both of them can be triggered due to any reason.

In the absence of a healthy immune system, there is no chance of survival by a human as there is a limit up to which the precautions can be taken to avoid a particular disease, but once it took place in the body of the individual, he won’t be having a strong immune system and hence will not be able to survive.


  1. https://www.pnas.org/content/93/1/7.short
  2. https://www.cabdirect.org/cabdirect/abstract/19342700805
  3. https://www.annualreviews.org/doi/abs/10.1146/annurev.micro.51.1.311
  4. https://www.sciencedirect.com/science/article/pii/0019279169901773
  5. https://diabetes.diabetesjournals.org/content/22/6/429.short
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