What do the determinants on an antigen primarily interact with?

The determinants on an antigen, also known as epitopes, primarily interact with antibodies. Epitopes are specific parts of the antigen that are recognized by the immune system, particularly by antibodies produced by B cells. When an antigen is encountered, the immune system generates antibodies that specifically bind to these epitopes, initiating a response against the foreign substance.

This interaction is crucial for the immune response, as it allows the body to identify and target pathogens such as bacteria and viruses. Once the antibody binds to the epitope, it can neutralize the pathogen directly or mark it for destruction by other components of the immune system, such as phagocytes.

Understanding this interaction helps to clarify the role of antibodies in the immune response and highlights their specificity. The unique shape and structure of each epitope allow antibodies to specifically target a wide variety of antigens, which is fundamental to the adaptive immune response.