SQ-NHS is an organic compound containing sulfaquinoxaline structure and N-hydroxysuccinimide ester (NHS ester), with a molecular weight of approximately 614. Its core is composed of two indole rings (one containing chlorine and the other containing ethyl) connected by a methylene bridge to cyclobutenedione, and the terminal NHS ester group endows it with high reactivity. This compound can efficiently covalently bind with primary amines (such as lysine residues in proteins and peptides) under weakly alkaline conditions, generating stable amide bonds. It is widely used in biological labeling, fluorescence imaging, and biological conjugation. Its green fluorescence characteristics (excitation wavelength 491nm, emission wavelength 518nm) support cell tracking and detection, and require light avoidance and low-temperature drying storage to ensure stability.

CAS number: 154161-81-6

Chinese name: sulfaquinoxaline-N-hydroxysuccinimide ester; SQ-N-hydroxysuccinimide ester

English name: SQ-NHS; SQ-N-hydroxysuccinimide ester

Molecular formula: C ∝₄ H ∝₂ ClN ∝ O ₆

Molecular weight: 614.09

Purity: ≥ 95%

Storage conditions: Freeze and dry below -20 ℃ to avoid repeated freeze-thaw cycles

Structural formula:

Security protection:

During the operation, disposable protective clothing, masks and other protective equipment should be worn to ensure self safety.

This reagentonly useIn scientific research

Reactivity and Application

Reactivity of NHS ester groups:

Reaction with amino groups: NHS esters can undergo nucleophilic substitution reactions with primary amines (such as lysine residues in proteins and peptide chains) to form stable amide bonds. This characteristic makes it a commonly used tool for biological molecular markers.

Reaction conditions: Usually carried out under weakly alkaline conditions (pH 7.2-8.5) to promote deprotonation of amino groups and activation of NHS esters.

【 Application Fields 】

Biomarkers and Imaging: Fluorescent labeling of proteins, antibodies, or peptides for cell imaging, flow cytometry, or immunohistochemistry.

Bioconjugation: covalently linking fluorescent molecules, biotin or other functional groups to biomolecules to construct probes or carriers.

Materials Science: Used to modify the surface of polymers or nanomaterials, introducing biocompatibility or targeting functions.

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The above content is edited and organized by YNN of Xi'an Kaixin Biotechnology Co., Ltd

This reagent is only used for scientific research experiments and cannot be used on the human body