Methyltetrazine-amido-PEG7-azide | CAS 2112731-46-9

Methyltetrazine-amido-PEG7-azide is a multifunctional bioconjugation reagent that combines a methyltetrazine click handle with an azide for orthogonal labeling workflows. The molecule is built around an amide-linked PEG7 spacer that improves aqueous solubility and reduces steric constraints during biomolecular coupling and surface functionalization. As a click-chemistry platform, it is commonly used to install tetrazine functionality for fast inverse-electron-demand Diels–Alder reactions while also providing an azide for secondary conjugation strategies in probe, material, and imaging-reagent development.

1. Tetrazine Probe Labeling

Methyltetrazine-amido-PEG7-azide is used to generate tetrazine-bearing probes for rapid bioorthogonal conjugation to complementary strained alkenes or trans-cyclooctenes on targets such as peptides, proteins, and polymeric scaffolds. The PEG7 spacer helps maintain accessibility of the reactive tetrazine group in complex biological buffers, supporting consistent labeling in research workflows that require fast kinetics and minimal cross-reactivity. Researchers often choose this reagent when they need a single construct that can be incorporated into a probe design and later paired with an orthogonal click partner for downstream assembly.

2. Orthogonal Multistep Conjugation

Methyltetrazine-amido-PEG7-azide enables multistep labeling schemes where azide-based attachment is performed separately from tetrazine-based ligation. The presence of both functional handles supports sequential build-up of complex conjugates, including staged installation of targeting motifs followed by assembly of reporter components or enrichment tags. This dual-function design is particularly valuable for workflows that require careful control over labeling order, such as preparing libraries of conjugates for assay development, imaging reagent optimization, or platform prototyping in chemical biology.

3. Surface and Hydrogel Functionalization

Methyltetrazine-amido-PEG7-azide is applied to functionalize material surfaces and water-compatible polymer networks where click handles are required for subsequent coupling to biomolecules or imaging reporters. The azide functionality supports azide-reactive coupling strategies for immobilizing the reagent onto surfaces, while the methyltetrazine moiety provides a reactive site for later attachment of complementary click partners. PEG7 spacing can reduce nonspecific interactions and improve presentation of reactive groups within hydrated environments, making the reagent useful in biomaterials research that relies on modular, orthogonal surface chemistry.

4. Molecular Imaging Reagent Assembly

Methyltetrazine-amido-PEG7-azide is used as a modular building block for constructing imaging and detection reagents that incorporate tetrazine-based click ligation steps. Teams developing fluorescent or other signal-bearing conjugates often use this reagent to introduce a tetrazine handle into a larger probe architecture, then perform rapid conjugation to complementary reporter-bearing components under bioorthogonal conditions. The azide handle further supports iterative probe refinement, such as attaching additional tags, affinity elements, or purification handles during reagent assembly for molecular imaging and diagnostic-reagent development.