Methyltetrazine-PEG12-acid | CAS 2183440-39-1

Methyltetrazine-PEG12-acid is a PEGylated methyltetrazine click chemistry reagent built for fast, bioorthogonal inverse-electron-demand Diels–Alder reactivity with trans-cyclooctene (TCO) partners. The extended PEG12 spacer and terminal carboxylic acid support aqueous handling and downstream conjugation or surface immobilization, making the reagent well suited for modular labeling workflows in chemical biology and biomaterials research. Its tetrazine functionality is commonly leveraged to generate stable conjugates for imaging probes, affinity reagents, and material functionalization where controlled, orthogonal coupling is required.

1. Pre-Targeted Imaging Probes

Methyltetrazine-PEG12-acid is used as a tetrazine-bearing component in pre-targeting style probe architectures, where a tetrazine handle enables rapid capture of a TCO-tagged partner after separate preparation steps. Researchers incorporate the PEG12 spacer to improve solubility and reduce nonspecific interactions during probe assembly in complex biological buffers, while the terminal acid supports standardized coupling chemistry for attaching the reagent to carriers such as polymers, nanoparticles, or scaffolded targeting ligands. This application is especially common in molecular imaging tool development, where modular exchange of tetrazine and TCO components supports rapid iteration of probe formats and multivalent designs.

2. Antibody And Ligand Conjugation

Methyltetrazine-PEG12-acid is frequently selected for preparing tetrazine-functional antibody derivatives and affinity ligands used in biochemical assays and imaging reagent development. The PEG12 linker helps maintain accessibility of the tetrazine moiety and can mitigate steric shielding that would otherwise slow productive engagement with TCO-functional counterparts. The carboxylic acid functionality enables straightforward integration into established bioconjugation pipelines, including formation of activated ester intermediates for coupling to amine-bearing biomolecules or incorporation into linker systems for controlled density on protein surfaces. In these workflows, the reagent serves as a reliable, modular click handle for building conjugates with defined architectures.

3. Cell Surface And Membrane Labeling

Methyltetrazine-PEG12-acid is applied in chemical biology for labeling experiments that require orthogonal, rapid conjugation to TCO-functional targets presented on cell surfaces or membrane-associated constructs. The PEG12 spacer is advantageous for aqueous labeling conditions because it promotes dispersion and improves the effective reach of the tetrazine group toward TCO partners on heterogeneous surfaces. The terminal acid allows the reagent to be incorporated into linker strategies that support consistent labeling density and compatibility with downstream purification or analytical readouts. This use case is common in workflows that generate clickable membrane tags, surface reporters, and multicomponent labeling panels for mechanistic studies and assay development.

4. Functionalized Biomaterials Surfaces

Methyltetrazine-PEG12-acid is used to introduce tetrazine functionality onto biomaterial surfaces and polymeric platforms intended for subsequent capture of TCO-bearing molecules. The PEG12 chain supports wetting and reduces aggregation on hydrophilic materials, while the carboxylic acid enables attachment through standard surface coupling chemistries to create stable, reactive interfaces. Material developers rely on this reagent to build modular surfaces for immobilizing probes, assembling layered constructs, and creating reusable capture layers where TCO-functional components can be exchanged or sequentially added. Such approaches are common in diagnostic reagent development and materials-based assay engineering, where spatially controlled conjugation and orthogonal assembly are key requirements.