Methylamino-PEG5-azide | CAS 2055046-24-5

Methylamino-PEG5-azide is a PEG-based azide click chemistry reagent featuring a terminal azide for copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) and a methylamino handle for downstream conjugation workflows. The flexible PEG5 spacer supports solubility and reduces nonspecific interactions in labeling and biomolecule modification, making it a common building block for research-grade bioconjugation. Its azide functionality enables modular attachment to alkyne-bearing probes, surfaces, and materials, which is why it is frequently selected for probe construction, linker installation, and PEGylated conjugate preparation.

1. Biomolecule Surface Labeling

Methylamino-PEG5-azide is widely used to install a PEG spacer and a clickable azide group onto proteins, peptides, and other biomolecular platforms when alkyne-functional partners are available for subsequent CuAAC coupling. Researchers often choose this reagent to improve aqueous handling and to help control conjugate architecture, particularly when minimizing steric crowding and nonspecific adsorption is important for imaging reagents, affinity reagents, or analytical standards. The methylamino functionality further supports flexible downstream derivatization strategies, enabling integration into multi-step labeling schemes used in chemical biology and biomaterials research.

2. PEG Linker Installation

Methylamino-PEG5-azide serves as a practical PEG linker for constructing modular conjugates where a defined, flexible distance between functional groups is required. In workflows that rely on azide–alkyne click to connect two components, the PEG5 segment helps maintain accessibility of the attached moieties, which is valuable for building fluorescent tags, affinity handles, and enzyme- or binder-associated reagents. Many teams incorporate Methylamino-PEG5-azide during reagent development to tune solubility and reduce aggregation tendencies in conjugate libraries, especially when the final target contains hydrophobic dyes, bulky ligands, or multivalent binding elements.

3. Molecular Imaging Probe Construction

Methylamino-PEG5-azide is commonly integrated into molecular imaging and detection reagent pipelines to create clickable handles for attaching imaging reporters to targeting or scaffold components. By providing an azide for CuAAC coupling to alkyne-bearing fluorophores, radiochemistry precursors, or signal-generating tags, it supports rapid assembly of probe candidates with consistent linker length and improved colloidal behavior. The PEG5 spacer is particularly useful when probe performance depends on maintaining reporter accessibility and limiting nonspecific interactions during assay development and imaging optimization.

4. Diagnostic and Assay Reagent Building

Methylamino-PEG5-azide is used to generate assay-ready conjugates for diagnostic reagent development and analytical assays that require robust, modular coupling chemistry. Laboratories often employ this reagent to introduce an azide-functional PEG linker into capture molecules, labeling reagents, or assay components that are later connected to alkyne-functional reporters, nanoparticles, or solid-phase surfaces via click chemistry. The methylamino group offers additional flexibility for orthogonal functionalization steps within multicomponent assay designs, supporting workflows that prioritize reproducible conjugate architecture and efficient reagent assembly.