cross-linking

in biomolecules
https://doi.org/10.1351/goldbook.09867

Formation of a covalent bridge between two biomacromolecules or between two segments of the same biomacromolecule using reactive substances (e.g. formaldehyde, bifunctional aldehydes such as glutaraldehyde, or cisplatin) or photochemical processes.

Note: Cross-linking is used to study protein oligomerization, as well as protein–protein and nucleic acid–protein interactions
Source:
PAC, 2018, 90, 1121. (Terminology of bioanalytical methods (IUPAC Recommendations 2018)) on page 1183 [Terms] [Paper]