Methyltetrazine-PEG24-NHS ester | CAS 2055646-25-6

Methyltetrazine-PEG24-NHS ester is a PEGylated NHS ester click chemistry reagent that pairs a methyltetrazine functional group with an amine-reactive N-hydroxysuccinimide ester for stable conjugation to primary amines. As a tetrazine-based component, it is widely used as the “click partner” in fast inverse electron-demand Diels–Alder (IEDDA) bioorthogonal ligation workflows, enabling subsequent attachment of probes, handles, or imaging/assay moieties to biomolecules and surfaces. The long PEG spacer improves aqueous compatibility and reduces steric constraints, making the reagent particularly relevant for labeling, surface functionalization, and multistep probe assembly in chemical biology and molecular imaging tool development.

1. Protein Labeling Workflows

Methyltetrazine-PEG24-NHS ester is commonly used to install tetrazine functionality onto proteins and peptide carriers through NHS-ester coupling to lysine residues or N-terminal amines. Researchers rely on the PEG24 spacer to maintain labeling accessibility and to support efficient downstream IEDDA coupling with strained alkenes or trans-cyclooctene-bearing partners used for sequential probe assembly. This reagent is frequently selected for building modular conjugates such as tetrazine-functionalized antibodies, enzyme scaffolds, or affinity proteins that later receive fluorescent dyes, affinity tags, or other imaging handles under mild, bioorthogonal conditions.

2. Antibody and Affinity Conjugates

Methyltetrazine-PEG24-NHS ester supports antibody conjugation strategies where controlled attachment of tetrazine groups is needed for later click-based installation of imaging reagents or analytical reporters. The amine-reactive NHS ester allows straightforward functionalization of antibody frameworks, while the PEG spacer helps preserve binding-related accessibility and reduces nonspecific interactions during labeling and handling. In molecular imaging and diagnostic reagent development, tetrazine-functional antibodies prepared with Methyltetrazine-PEG24-NHS ester are often used as central targeting platforms for subsequent conjugation steps that generate multicomponent probes with defined valency and flexible modularity.

3. Surface and Material Functionalization

Methyltetrazine-PEG24-NHS ester is applied to functionalize solid supports and biomaterials that present accessible primary amines, including activated polymer surfaces, porous matrices, and amine-rich coatings used in assay and sensing formats. By coupling tetrazine moieties through the NHS ester, laboratories can create clickable interfaces that capture or assemble complementary strained-alkene reagents for immobilized labeling, signal generation, or multistep surface patterning. The PEG24 linker is particularly valuable for maintaining reagent mobility at the interface, improving contact between surface-bound tetrazines and incoming click partners, and supporting reproducible performance in materials-based research workflows.

4. Multistep Probe Assembly

Methyltetrazine-PEG24-NHS ester is widely used as a strategic intermediate for building complex probe architectures where tetrazine functionality must be introduced first and additional components are added later via click chemistry. Teams developing fluorescent, luminescent, affinity, or enrichment reagents often functionalize a biomolecule or scaffold with Methyltetrazine-PEG24-NHS ester, then perform a subsequent IEDDA ligation to attach the desired reporter or capture element. This two-step approach is favored for its modularity: it decouples amine-reactive installation from the final probe composition, enabling rapid iteration of probe design for imaging toolkits, assay reagent libraries, and chemical biology studies requiring orthogonal assembly.