cross-link

1. a covalent bond that links two chains of atoms, or two sections of one chain, in a polymeric molecule; the cross-link is created by a third bond in a monomer unit in addition to the two bonds forming the polymeric chain; -- a cross-link may be internal to a single chain, rather than between two otherwise unlinked chains; as, ultraviolet irradiation creates cross-links between the two chains of a DNA double helix; many enzymes have cross-links formed by disulfide bonds; polystyrene resins have their porosity controlled by the proportion of cross-links. Called also cross-linkage. (Chem., Biochem.)

imp. & p. p. cross-linked; p. pr. & vb. n. cross-linking

1. to create cross links in; -- of polymeric molecules. (Chem., Biochem.)