Difference Between Antiserum and Antibody

The key difference between antiserum and antibody is that antiserum is blood serum that is rich in specific antibodies against an infective organism or a poisonous substance, while antibody is an immunoglobulin protein that identifies and binds with foreign antigens that enter into our bloodstream.

Antibodies play a major role in our immune system by identifying foreign pathogens such as viruses, bacteria, toxins, fungal spores, etc. and protecting us by successfully neutralizing them. Antibodies are Y shaped proteins and immunoglobulins produced by plasma cells. They are present in the blood serum and the other bodily fluids. Antiserum is antibody-rich serum extracted from an immunized animal or a person. A particular antiserum contains a higher concentration of preformed specific antibody. Hence, it is very useful in the treatments of specific diseases.

CONTENTS

1. Overview and Key Difference
2. What is Antiserum 
3. What is Antibody
4. Similarities Between Antiserum and Antibody
5. Side by Side Comparison – Antiserum vs Antibody in Tabular Form
6. Summary

What is Antiserum?

Antiserum is blood serum that is rich in a specific antibody. Therefore, antiserum contains a higher concentration of a particular antibody developed against a particular antigen.

To extract antiserum, it is necessary to inject an animal or a person with a specific antigen. Once injected, antibody production takes place against that particular antigen inside the animal. After that, blood serum can be extracted and concentrated. We often use antiserums in passive immunization, against specific diseases such as Ebola, diphtheria and tetanus, etc.

What is Antibody?

Antibodies are immunoglobulin proteins that play a major role in the immune system. They have a ‘Y’ shaped structure. They identify foreign substances, which are antigens. Moreover, they detect the presence of pathogenic organisms and successfully eliminate them without allowing the pathogens to cause harm to the host organism. Antibodies are of five different types: IgM, IgG, IgA, IgD, and IgE.  Moreover, according to the type of binding of an antibody with an antigen (directly or indirectly), antibodies have two types as primary antibody and secondary antibody. Primary antibodies have the ability to bind with the antigen directly while a secondary antibody doesn’t bind to the antigen directly, but form interactions through binding to the primary antibody.

The antibody has a portion known as paratope (antigen-binding site present in the tip of the ‘Y’ shaped structure) to identify and bind with the complementary structure of the antigen, which is the epitope. Paratope and epitope work as ‘lock’ and ‘key’, respectively. It allows the proper binding of the antigen with the antibody. The effect of the antigen is directly proportional to the type of antigen. Once the antibody binds with antigen, it activates other immune responses like the action of macrophages to destroy the foreign pathogenic agent. For activation, an antibody communicates with the other components of the immune system by the Fc region present in the base of the ‘Y’ shaped structure of the antibody.

What are the Similarities Between Antiserum and Antibody?

• Antiserum contains a higher concentration of antibodies.
• Both antibody and antiserum provide specific immunity.

What is the Difference Between Antiserum and Antibody?

The key difference between antiserum and antibody is that antiserum is the blood serum we obtain from an immunized host, while antibody is an immunoglobulin protein that detects the presence of antigens and aid in neutralizing them.

Moreover, antiserum contains water, antibodies, dissolved solutes, etc., while antibody is a protein molecule. So, this is another difference between antiserum and antibody.

Summary – Antiserum vs Antibody

Antiserum is antibody-rich serum obtained from an immunized host. On the other hand, the antibody is a Y shaped protein that detects the presence of foreign antigens and helps the immune system to neutralize them. So, this is the key difference between antiserum and antibody. Antiserum is the serum used in passive immunization against many diseases.

Reference:

1. “Antiserum.” Wikipedia, Wikimedia Foundation, 14 June 2019, Available here.
2. “Antibody.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 17 Apr. 2019, Available here.

Image Courtesy:

1. ” immunization, children, doctors, office”  (CC0) via Pixino
2. “Antibody” By Fvasconcellos 19:03, 6 May 2007 (UTC) – Color version of Image:Antibody.png, originally a Work of the United States Government (Public Domain) via Commons Wikimedia