(5,6)-FAM diacetate NHS ester, 25 mg

(5,6)-FAM diacetate NHS ester is a high-purity fluorescent labeling reagent widely used for bioconjugation of amines, peptide labeling, and protein fluorescence assays. The N-hydroxysuccinimide (NHS) ester group reacts efficiently with primary amines on lysine residues or N-termini to form stable amide linkages, enabling bright, long-lasting fluorescein-based labeling for imaging, flow cytometry, or in-gel detection.

This compound contains diacetate-protected carboxyfluorescein (FAM), improving its solubility and stability prior to activation. Upon deacetylation, (5,6)-FAM exhibits strong green fluorescence (λ_ex ≈ 495 nm, λ_em ≈ 520 nm), comparable to FITC, making it ideal for sensitive detection and quantification of labeled biomolecules.