TCO PEG4 NHS succinate is a highly reactive amine-targeting reagent used in bioorthogonal chemistry. It features a strained trans-cyclooctene (TCO) moiety linked to an NHS carbonate group via tetra(ethylene glycol) spacer, enabling efficient conjugation to primary amines on biomolecules such as proteins, peptides, or small molecules.

This reagent plays a pivotal role in constructing advanced bioconjugates for imaging or drug delivery. By introducing the TCO moiety onto amine-containing substrates, researchers can prepare molecules that undergo rapid and selective click reactions with tetrazines. TCO PEG4 NHS succinate is especially valuable for synthesizing cleavable linkers and multifunctional cross-linkers.