TCO-PEG6-amine | CAS 2353409-94-4

TCO-PEG6-amine is a trans-cyclooctene (TCO) functionalized, PEG6-extended amine click chemistry reagent designed for strain-promoted inverse electron-demand cycloaddition (SPAAC-type) with tetrazines. Its flexible PEG spacer and terminal amine make it well-suited for downstream conjugation to biomolecules, surfaces, and polymeric carriers while maintaining accessibility of the TCO handle for rapid tetrazine-mediated labeling. As a widely used bioorthogonal building block, TCO-PEG6-amine supports modular workflows in molecular imaging, diagnostic reagent development, and materials functionalization where controlled presentation of the cyclooctene moiety is critical.

1. Tetrazine Probe Conjugation

TCO-PEG6-amine is commonly used to prepare tetrazine-reactive labeling partners for fluorescence, affinity, and imaging reagent platforms. The PEG6-amine handle enables coupling to targeting ligands such as antibodies, antibody fragments, peptides, and nucleic-acid binders, while the TCO group provides a bioorthogonal handle for subsequent tetrazine-based probe attachment. This separation of conjugation steps helps teams build consistent probe architectures with predictable linker length and improved accessibility of the reactive TCO for efficient tetrazine engagement during assay preparation.

2. Antibody and Ligand Labeling

TCO-PEG6-amine is frequently selected for antibody and ligand functionalization workflows that require site-accessible click handles without extensive redesign of the targeting moiety. Researchers and diagnostic reagent developers use the amine functionality to incorporate the TCO handle into antibody conjugates or ligand scaffolds, then perform tetrazine-mediated “late-stage” labeling with reporter payloads such as dyes, enzyme substrates, or imaging tags. The PEG spacer supports reduced steric hindrance around the cyclooctene, which is particularly valuable when labeling large proteins or multivalent ligand formats intended for high-throughput assay development.

3. Surface and Material Functionalization

TCO-PEG6-amine is applied to functionalize biomaterials and solid supports that benefit from modular, click-based immobilization strategies. The amine group supports attachment to activated surfaces, coatings, and polymer matrices, while the TCO moiety enables subsequent tetrazine-mediated grafting of fluorescent reporters, affinity capture elements, or other chemical functionalities. This approach is used in platform development for biosensing and assay manufacturing where reproducible surface presentation of reactive handles and linker flexibility can influence binding performance and signal stability.

4. Multivalent Imaging Reagents

TCO-PEG6-amine is well suited for constructing multivalent imaging and detection reagents that rely on controlled spacing between targeting units and reporter payloads. Teams use the PEG6-amine to tune conjugate geometry when attaching TCO handles to scaffolds such as nanoparticles, dendrimers, or polymer backbones, then employ tetrazine reagents to install imaging moieties in a controlled, modular manner. The resulting architecture supports scalable preparation of probe libraries for assay optimization and reagent screening, where consistent linker length and accessible click functionality are essential for downstream workflows.