Antigens: Viral and Bacterial Antigens for Immunological Assays

Antigens are substances that can elicit an immune response in a host, specifically by activating lymphocytes or causing antibody production. They are classified as either foreign or self-antigens depending on whether they enter the body or originate within the body, respectively. Foreign antigens include bacteria, viruses, parasites, chemicals, or even proteins and toxins found in food. In contrast, self-antigens often include mutated or overexpressed proteins.

The portion of an antigen that is recognized by antigen specific receptors on T and B cells or by antibodies is called the epitope or antigenic determinant. Those that elicit strong immune responses are described as highly immunogenic. An antigen is primarily defined by its ability to bind to the variable Fab region of an antibody, and whole antigen or specific epitopes are routinely used to generate antibodies for research purposes. Most research applications rely on the binding of antibodies to target antigens.

Bio-Rad offers antigens in a variety of formats, which include purified, antigen carrier conjugates, ascites and inactivated pathogens.