XFD488 Hydroxylamine *Same Structure to Alexa Fluor™ 488 Hydroxylamine*

• Ex/Em: 499/520 nm
• Extinction coefficient: 71,000 cm^-1M^-1
• Reactive Group: Hydroxylamine
• Conjugation Versatility: Reacts with aldehydes/ketones via hydrazide or hydroxylamine groups, forming stable oxime or hydrazone linkages
• Bright and Stable: Offers high fluorescence intensity, photostability, and consistent performance across pH 4—10
• Hydrophilic: Prevents aggregation and enhances signal clarity for advanced imaging and live-cell applications

XFD488 Hydroxylamine is the same molecule to Alexa Fluor® 488 Hydroxylamine with higher purity (Alexa Fluor® is the trademark of ThermoFisher). The fluorescent dye hydrazides and hydroxlamines are reactive molecules that can be used to add a fluorescent label to biomolecules containing aldehydes or ketones. Aldehydes and ketones can be introduced into polysaccharides and glycoproteins by periodate-mediated oxidation of vicinal diols. Galactose oxidase can also be used to oxidize terminal galactose residues of glycoproteins to aldehydes. Hydroxylamine derivatives (aminooxy compounds) react with aldehydes and ketones to yield oximes. Oximes are superior to hydrazones with respect to hydrolytic stability. Both hydrazones and oximes can be reduced with sodium borohydride (NaBH4) to further increase the stability of the linkage. In addition, fluorescent dye hydrazides and hydroxlamines are useful as low molecular weight, membrane-impermeant, aldehyde-fixable cell tracers.