Immunogen is any antigen that is capable of inducing humoral or
cell mediated response rather than immunological tolerance.This
ability is called immunogenicity.
An immunogen is a type of antigen or any substance which may be
bound by components of immune system specifically.
The term antigen , arises from the ability to induce generation
of anti bodies.
Despite all the antigen which are recognized by
specific lymphocyte or antibody and cannot evoke immune
response are not immunogen, only those antigen which can evoke
immune response , when recognized by antigen or antibody is called
immunogen.
An explicit example of immunogen is Hapten, which is low
molecular weight compounds that may be bound by antibodies.