Hapten
Definition
A small molecule with antigenicity but no immunogenicity on its own. Haptens must be conjugated to a carrier protein to raise antibodies. Common forensic examples include drug metabolites (morphine, benzoylecgonine), some pesticide residues, and certain explosives residues detected by immunoassay.
Related terms
- Antigen
- A molecule recognised by the adaptive immune system through specific binding to an antibody or T-cell receptor. Defined by immunogenicity (capacity to...
- Cross-reactivity
- The capacity of an antibody raised against one analyte to bind structurally related compounds. In RIA, cross-reactivity is the main driver of...
- Epitope
- The specific region of an antigen that makes physical contact with an antibody's binding site (paratope). Also called the antigenic determinant. A...
- Immunogen
- A molecule that is both immunogenic (triggers antibody production) and antigenic (binds those antibodies). Used interchangeably with 'complete antigen'. Most protein antigens...
- Secretor status
- A genetic trait that determines whether a person expresses their ABO blood group antigens in secreted body fluids such as saliva, semen,...
Explained in
- Antigens: Structure, Types, and Forensic RelevanceA small molecule with antigenicity but no immunogenicity on its own. Haptens must be conjugated to a carrier protein to raise antibodies. Common forensic examp...