An antigen is a protein made in response to a specific antigen.
The specific protein made in response to a particular antigen is called an antibody.
antibody
The protein that elicits an immune reaction in blood cells is called an antigen. Antigens are typically foreign substances that trigger an immune response when they are detected by the immune system.
Depending on the exact response, the substance is generally called a pathogen, yet more specifically depending on the nature of the response and origin of the substance, could be an antigen, allergen, carcinogen, etc.
Antigen
The prostate-specific antigen (PSA) test is a blood screen for prostate cancer.
HLA (Human Leukocyte Antigen) is called an antigen because it is a protein on the surface of cells that plays a crucial role in the immune system. When the immune system recognizes foreign antigens, including those of HLA, it triggers an immune response to protect the body from pathogens.
Antigen
Allergy
Antigens are protein substances formed in the blood to destroy foreign substances. Antigens can also be administered artificially in some cases.
Memory cell. Memory cells are a type of immune cell that remember specific antigens upon initial exposure, allowing for a faster and more effective response upon subsequent exposure to the same antigen.
Any foreign particle interact with Antibody or T cell is antigen. Interaction is non-covalent and highly specific. Antigen that evoke immune response is called Immunogen. An immunogen usually has a fairly high molecular weight (usually greater than 10,000), thus, a variety of macromolecules such as proteins,lipoproteins, polysaccharides, some nucleic acids, and certain of the teichoic acids, can act as immunogens.