When you have been exposed to a particular antigen, your body produces antibodies specific to that virus are able to quickly eliminate any future infections.
Another type of test looks for the presence of polymerase chain reaction (PCR) which identifies the specific chemical character of the antigen in its DNA, according to a 2001 study in Veterinary Ophthalmology.
A person who inherits an A antigen gene from each parent has type A blood; receiving two B antigen genes corresponds with type B blood; and inheriting A and B antigen genes means a person has type AB blood.
Rh blood incompatibility-Incompatibility between the blood of a mother and her baby due the absence of the Rh antigen in the red blood cells of one and its presence in the red blood cells of the other.
If a radically different blood type is introduced into the bloodstream, the immune system produces antibodies, proteins that specifically attack and destroy any cell carrying the foreign antigen.
Inactivated-rabies vaccines are injected, either before or after exposure to the virus, in 1.0-ml. doses containing at least 2.5 IU/ml. of rabies virus antigen.
Second, I can duplicate the DNA with some time in my lab and isolate the antigen, meaning I can make someone immune to our enemies' powers.
The molecules which lead to the production of anti-substances are usually known as antigens, and each antigen has a specific combining affinity for its corresponding anti-substance, fitting it as a lock does a key.
In the first group, the anti-substance simply combines with the antigen, without, so far as we know, producing any change in it.
In the second group, the anti-substance, in addition to combining with the antigen, produces some recognizable physical change in it; the precipitins and agglutinins may be mentioned as examples.