AAT Bioquest offers a comprehensive selection of crosslinkers for bioconjugation applications, including heterobifunctional reagents, photoaffinity probes, click chemistry building blocks, and preactivated proteins. These reagents enable efficient coupling of biomolecules through various reactive groups targeting amines, thiols, and other functional moieties. Our portfolio includes our proprietary Buccutite™ crosslinking technology for high-efficiency protein-protein conjugation, as well as classic NHS ester and maleimide reactive chemistries that are designed to work in combination with crosslinkers to streamline conjugation workflows.

Buccutite™ technology represents a breakthrough in protein-protein conjugation, utilizing a proprietary MTA-FOL coupling chemistry that provides higher conjugation yields while preserving biomolecule activity. Unlike traditional NHS ester chemistry that can over-modify proteins, Buccutite™ crosslinking produces more consistent conjugates with predictable stoichiometry.

Heterobifunctional crosslinkers containing both NHS ester (amine-reactive) and maleimide (thiol-reactive) groups enable controlled two-step conjugation between proteins. The NHS ester first reacts with primary amines to form stable amide bonds, followed by maleimide conjugation to free sulfhydryls. This approach minimizes unwanted homo-conjugation and allows sequential coupling of two different biomolecules.

Click chemistry-based crosslinkers enable bioorthogonal conjugation through highly selective azide-alkyne reactions. DBCO (dibenzocyclooctyne) reagents undergo copper-free strain-promoted alkyne-azide cycloaddition (SPAAC), making them ideal for live cell applications and sensitive biomolecules where copper catalysts may cause toxicity or interference.

Photoaffinity crosslinkers contain light-activated moieties (diazirine, benzophenone, or phenyl azide) that form covalent bonds upon UV irradiation. These reagents are invaluable for studying transient protein-protein interactions, mapping binding sites, and identifying unknown interaction partners. Diazirine-based probes offer advantages including smaller size, stability in the dark, and efficient activation at approximately 350 nm.

Psoralens are photoactivatable DNA intercalators that form covalent crosslinks with pyrimidine bases upon UV irradiation. These derivatives (MOP and TMP variants) are conjugated with reactive handles for developing nucleic acid probes and studying DNA structure and interactions. Psoralen crosslinking is widely used for DNA-protein interaction studies and antisense applications.