The paired immunoglobulin fragments composed of the variable domains of the heavy and light chains.

That region of the immunoglobulin molecule that varies in its amino acid sequence and composition, and comprises the binding site for a specific antigen. It is located at the N-terminus of the Fab fragment of the immunoglobulin. It includes hypervariable regions (COMPLEMENTARITY DETERMINING REGIONS) and framework regions.

Synonyms: Immunoglobulin Fv Fragments, Fragments, Fv, Fv Antibody Fragment, Fv Fragments, Regions, Immunoglobulin Variable, Immunoglobulin Framework Region, Fragment, Fv Antibody, Framework Region, Immunoglobulin, Variable Region, Immunoglobulin, Fv Fragment, Ig Framework Region, Fv Antibody Fragments, Antibody Fragment, Fv, Variable Regions, Ig, Immunoglobulin V, Immunoglobulin Variable Regions, Immunoglobulin Variable Region, Framework Regions, Ig, Fv Fragments, Immunoglobulin, Variable Region, Ig, Antibody Fragments, Fv, Ig Variable Regions, Ig Variable Region, Variable Regions, Immunoglobulin, Fragments, Fv Antibody, Framework Region, Ig, 0, Fragments, Immunoglobulin Fv, Immunoglobulin Fv Fragment, Fragment, Immunoglobulin Fv, Ig Framework Regions, Fv Fragment, Immunoglobulin, Immunoglobulin Framework Regions, Fragment, Fv, Framework Regions, Immunoglobulin