How Polyclonal Antibodies are Produced

Posted by eliteinternet on October 25th, 2019

Researchers use antibodies for diagnostic purposes by injecting a lab animal such as a sheep, rabbit, or goat with a particular antigen.  After a few weeks, the animal’s immune system produces high levels of antibodies that correspond to the antigen.  These antibodies can then be used to create an antiserum.  An antiserum is a whole serum taken from the animal after the exposure to the given antigen.  The majority of antigens are complex structures, having multiple epitomes, resulting in the production of several antibodies in the given laboratory animal.  The polyclonal antibody response is similar to the response of the human body’s immune system.  Antiserum taken from an animal will consist of replicas of B cells which respond to a certain epitomes on the antigen. 

Consider the following example that illustrates the process for taking polyclonal antibodies creased in response to a given antigen: Researchers inject antigen into an animal like a rabbit.  The antigen then activates B cells which cause the production of produces clones of the B cells as well as plasma cells. Polyclonal antibodies come from different B cells and are created in response to various epitopes on the antigen. Serum taken from the animal contains the polyclonal antibodies. 

The process works as follows. Lab animals like rabbits, goats, and sheep are injected twice with an antigen when they will be used to create antiserum.  The second injection serves a specific purpose, to activate memory cells that make IgG antibodies against an antigen.  As a result of the memory cell’s affinity maturation, there is a pool of antibodies with a higher average affinity.  This happens because of mutations in the immunoglobulin gene variable regions.  As a result, there are B cells with different antigen binding sites.  After re-exposure to the antigen, the B cells that are able to produce antibodies with higher affinity antigen-binding sites will multiply and increase more antibody than the lower-affinity counterparts.  A chemical that provokes a general immune system response stimulates more antibodies thanks to an adjuvant – a chemical that causes this reaction which is often combined with the antigen before injection. 

A problem occurs with antiserum that comes from animals.  The antiserum contains not only the antibodies that were introduced in the lab, but also antibodies from any other antigens to which the animal has been exposed in its life.  Because of this, it is critical that antiserum be purified so that these additional antibodies are removed.  After the purification process, it is possible to use the resulting material for research and diagnostic purposes. 

This is why when it comes to polyclonal antibody services, it is recommended to trust experienced professionals who are fully versed in custom antibody production.

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Joined: February 13th, 2018
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