Methyltetrazine-PEG24-amine HCl salt | CAS 2353410-18-9

Methyltetrazine-PEG24-amine HCl salt is a PEGylated amine-functionalized methyltetrazine click reagent designed for bioorthogonal tetrazine–TCO ligation. Its extended PEG spacer supports aqueous solubility and reduces steric constraints during conjugation, while the terminal amine enables straightforward coupling to activated carboxyl groups, NHS esters, or other electrophiles for downstream labeling workflows. This reagent is widely used in chemical biology and molecular imaging tool development where controlled, site-specific attachment of tetrazine handles to biomolecules, nanoparticles, and surfaces is required.

1. Antibody And Protein Labeling

Methyltetrazine-PEG24-amine HCl salt is used to introduce a tetrazine handle onto antibodies, antibody fragments, and other protein scaffolds that are subsequently functionalized via tetrazine–TCO click chemistry. The PEG24 spacer helps maintain binding-relevant conformations and improves conjugation practicality in buffered aqueous environments, which is valuable when preparing imaging probes, affinity reagents, or mechanistic labeling constructs. Researchers commonly pair the amine functionality with protein-compatible coupling chemistries to generate tetrazine-bearing bioconjugates that can be rapidly clicked to TCO-functional reporters, linkers, or multivalent imaging platforms.

2. Molecular Imaging Probe Development

Methyltetrazine-PEG24-amine HCl salt supports the modular assembly of imaging and detection reagents by providing a stable tetrazine moiety for late-stage attachment to TCO-tagged dyes, chelators, nanoparticles, or reporter constructs. The PEGylated architecture improves handling and reduces nonspecific interactions during probe formulation, which is particularly relevant for fluorescent, luminescent, or other optical readouts used in research imaging workflows. In probe development pipelines, the amine group provides a convenient handle for integrating the tetrazine unit into larger targeting or reporting assemblies, enabling consistent reagent interchangeability across labeling campaigns.

3. Nanoparticle And Surface Functionalization

Methyltetrazine-PEG24-amine HCl salt is applied to functionalize nanoparticles and engineered surfaces with tetrazine groups for subsequent click conjugation to TCO-bearing ligands or payloads. The PEG24 chain promotes colloidal stability and can mitigate surface crowding effects, supporting more reproducible coupling outcomes when decorating high-curvature or heterogeneous materials. Industrial and academic teams often use the amine functionality to anchor the reagent to activated polymer coatings, carboxylated surfaces, or linker systems, creating tetrazine-functional materials that can be clicked to fluorescent markers, affinity tags, or multicomponent diagnostic reagent assemblies.

4. Multivalent Targeting And Linker Design

Methyltetrazine-PEG24-amine HCl salt is frequently incorporated into multivalent targeting architectures where controlled spacing between binding elements and reactive handles is critical. The PEG24 spacer provides a tunable distance that can improve accessibility of the tetrazine group when preparing branched conjugates, polymeric linkers, or modular reagent libraries for chemical biology experiments. By leveraging the terminal amine for orthogonal attachment to carriers or targeting moieties, researchers can design multicomponent constructs that undergo efficient tetrazine–TCO ligation to assemble complex labeling reagents with consistent stoichiometry and flexible component swapping.