Methyltetrazine-PEG4-acid | CAS 1802907-91-0

Methyltetrazine-PEG4-acid is a PEGylated methyltetrazine click chemistry reagent designed for bioorthogonal reactivity in tetrazine-based inverse electron-demand Diels–Alder (IEDDA) ligation. Its tetrazine core provides the key recognition handle for rapid coupling with strained alkene/alkyne partners, while the PEG4-acid spacer supports aqueous solubility and practical conjugation workflows. The acid-functionalized PEG segment also makes it well-suited for preparing imaging and labeling reagents, where controlled hydrophilicity and linker stability are important for downstream bioconjugation and material labeling.

1. Fluorescent Probe Labeling

Methyltetrazine-PEG4-acid is widely used to install tetrazine-reactive handles onto molecular probes that require efficient post-labeling conjugation with strained fluorophore partners. Researchers in chemical biology and molecular imaging often incorporate this reagent into workflows for generating fluorescent conjugates for microscopy, flow cytometry, and cell-surface labeling assays, where PEG spacing helps reduce nonspecific interactions and improves labeling reproducibility in complex media. The PEG4-acid functionality supports straightforward handling during conjugate assembly, enabling consistent probe preparation for comparative studies across targets and labeling densities.

2. Antibody And Protein Conjugates

Methyltetrazine-PEG4-acid supports tetrazine-driven bioconjugation strategies for preparing protein conjugates such as antibody-derived constructs, enzyme conjugates, and affinity reagents. In bioconjugation chemistry, the PEG spacer is commonly leveraged to moderate steric effects and improve accessibility of the reactive tetrazine moiety on large biomolecules, which is particularly valuable when coupling to bulky strained partners. The acid-bearing PEG segment also facilitates integration into established linker and conjugation pipelines, allowing laboratories to generate reproducible protein labeling reagents for target-binding studies and multi-component assay development.

3. Molecular Imaging Reagent Assembly

Methyltetrazine-PEG4-acid is used as a tetrazine component in the assembly of imaging reagents that benefit from modular, strain-promoted coupling to imaging reporters. Molecular imaging groups frequently select tetrazine-PEG4 linkers to tune solubility and circulation-relevant physicochemical properties of probe constructs during synthesis of imaging-ready conjugates, including fluorescent and luminescent reporter systems. The reagent’s PEG4-acid architecture helps maintain colloidal stability during probe formulation and supports consistent coupling to strained imaging tags, enabling streamlined generation of probe libraries for comparative imaging experiments.

4. Surface and Biomaterial Functionalization

Methyltetrazine-PEG4-acid is applied to functionalize biomaterials and surfaces with tetrazine-reactive groups for subsequent attachment of strained molecules under bioorthogonal conditions. Biomaterials scientists use tetrazine-PEG linkers to create modular interfaces for immobilizing probes, capture ligands, or reporter molecules on hydrogels, polymer coatings, and assay platforms, where PEG spacing can improve accessibility and reduce surface crowding effects. The acid functionality supports practical incorporation into material-linker strategies, enabling reproducible surface labeling and enabling downstream patterning or multi-step assembly of functional materials for analytical and research instrumentation.