[File:Immunoglobulin basic unit.svg|thumb| 1. Fab region
2. Fc region
3. Heavy chain
4. Light chain with one variable (V_L) and one constant (C_L) domain
5. Fv region with paratope
6. Hinge regions]] A paratope, also called an antigen-binding site, is a part of an antibody which recognizes and binds to an antigen. It is a small region (of 15 to 22 amino acids) of the antibody's Fv region, part of the fragment antigen-binding (Fab region), and contains parts of the antibody's heavy and light chains. Each arm of the Y shape of an antibody monomer is tipped with a paratope, which is a set of complementarity determining regions.

[File:Immunoglobulin basic unit.svg|thumb| 1. Fab region
2. Fc region
3. Heavy chain
4. Light chain with one variable (V_L) and one constant (C_L) domain
5. Fv region with paratope
6. Hinge regions]] A paratope, also called an antigen-binding site, is a part of an antibody which recognizes and binds to an antigen. It is a small region (of 15 to 22 amino acids) of the antibody's Fv region, part of the fragment antigen-binding (Fab region), and contains parts of the antibody's heavy and light chains. Each arm of the Y shape of an antibody monomer is tipped with a paratope, which is a set of complementarity determining regions.