by crosslinking, the interactions can be stabilized, captured, and analyzed. Examples of some common crosslinkers are the imidoester crosslinker dimethyl suberimidate, the N-Hydroxysuccinimide-ester crosslinker BS3 and formaldehyde. Each of these crosslinkers induces nucleophilic attack of the amino group of lysine and subsequent covalent bonding via the crosslinker. The zero-length carbodiimide crosslinker EDC functions by converting carboxyls into amine-reactive isourea intermediates that bind to lysine residues or other available primary amines. SMCC or its water-soluble analog, Sulfo-SMCC, is commonly used to prepare antibody-hapten conjugates for antibody development. In-vitro cross-linking method, termed PICUP (photo-induced cross-linking of unmodified proteins), was developed in 1999. They devised a process in which ammonium persulfate (APS), which acts as an electron acceptor, and [[tris(bipyridine)ruthenium(II) chloride|tris-bipyridylruthenium (II) cation () are added to the protein of interest and irradiated with UV light. PICUP is more expeditious and high yielding compared to previous chemical cross-linking methods. In-vivo crosslinking of protein complexes using photo-reactive amino acid analogs was introduced in 2005 by researchers from the Max Planck Institute of Molecular Cell Biology and Genetics. In this method, cells are grown with photoreactive diazirine analogs to leucine and methionine, which are incorporated into proteins. Upon exposure to ultraviolet light, the diazirines are activated and bind to interacting proteins that are within a few ångströms of the photo-reactive amino acid analog (UV cross-linking). In material science Wide usage of the term cross-linking is also described as vulcanization in material science and engineering, mainly addressing the fast reaction between monomers and polymers and branches of rubber. Cross-linking or interlinking m of polymers can improve the mechanical properties of the polymeric material and also can improve the adhesion between two interfaces of the coating. Promote the mechanical properties of material Cross-linked polymers, monomers, and branches can improve the bulk mechanical properties of the material and mostly decrease the viscosity of non-solid materials. The earliest examples of crosslinking, linking long chains of polymers together to increase strength and mass, involved tires. Rubber was vulcanized with sulfur under heat, which created a link between latex models. Synthetically crosslinked polymers have many uses, including those in the biological sciences, such as applications in forming polyacrylamide gels for gel electrophoresis. Synthetic rubber used for tires is made by crosslinking rubber through the process of vulcanization. This crosslinking makes them more elastic. Hard-shell kayaks are also often manufactured with crosslinked polymers. In many hydraulic fracturing treatments, a delayed gel-cross-linker fluid