Skip to Content


Pronunciation: lig'and, li'gand


  1. Any individual atom, group, or molecule attached to a central metal ion by multiple coordinate bonds, the porphyrin portion of heme, the corrin nucleus of the B12 vitamins.
  2. An organic molecule attached to a tracer element, a radioisotope.
  3. A molecule that binds to a macromolecule, a ligand binding to a receptor.
  4. The analyte in competitive binding assays, such as radioimmunoassay.
  5. An atom or group covalently attached to a specified carbon atom in an organic molecule.

[L. ligo, to bind]

Disclaimer: This site is designed to offer information for general educational purposes only. The health information furnished on this site and the interactive responses are not intended to be professional advice and are not intended to replace personal consultation with a qualified physician, pharmacist, or other healthcare professional. You must always seek the advice of a professional for questions related to a disease, disease symptoms, and appropriate therapeutic treatments.
© Copyright 2018 Wolters Kluwer. All Rights Reserved. Review Date: Sep 19, 2016.