Definition of light chain in US English:

light chain

noun

Biochemistry
  • The protein subunit that, as one of a pair, forms part of the main antigen-binding region of an immunoglobulin molecule.

    • ‘This assay is highly sensitive to increasing concentrations of monoclonal free kappa or free lambda light chains in the serum of patients with evolving or relapsing myelomas.’
    • ‘The complete dissociation of all of the regulatory light chains was a precondition of later experiments.’
    • ‘Free kappa and lambda light chains are antibody fragments secreted by plasma cells in the bone marrow.’