Biotin-4-Fluorescein

RT

644, 69

Light yellow to dark yellow or light orange to dark orange powder

Biotin-4-Fluorescein is used to quantitate biotin binding sites. Biotin-4-Fluorescein is a reagent that binds to avidin more readily than conventional fluorescein biotin. This bifunctional biotin-fluorescein conjugate demonstrates better binding and stronger fluorescence than biotin fluorescein. It has similar avidin-binding properties in terms of high affinity, fast association, and non-cooperative binding to avidin and streptavidin tetramers. These exceptional properties are attributed to the small size/length of the new ligand since all larger/longer biotin derivatives are known for their mutual steric hindrance and anti-cooperative binding in 4:1 complexes with avidin and streptavidin tetramers. Specific binding of this biotin-fluorescein conjugate towards avidin and streptavidin is accompanied by 84-88% quenching of ligand fluorescence. It is used for the quantitation of biotin-binding sites. Both the fluorescence and absorbance of biotin-4-fluorescein are quenched upon binding to one of the four biotin-binding sites of streptavidin, avidin, or the streptavidin conjugates of fluorescent dyes or enzymes. As a result, when a known concentration of biotin-4-fluorescein is added to a known amount of streptavidin, one can estimate the number of biotin-binding sites.

Synonyms:
(3aS, 4S, 6aR)-N-[2-[[(3', 6'-Dihydroxy-3-oxospiro[isobenzofuran-1(3H), 9'-[9H]xanthen]-5-yl)carbonyl]amino]ethyl]hexahydro-2-oxo-1H-thieno[3, 4-d]imidazole-4-pentanamide

CAS Number:
1032732-74-3

Molecular Formula:
C₃₃H₃₂N₄O₈S

Molecular Weight:
644.69

Purity:
≥98%

Appearance:
Light yellow to dark yellow or light orange to dark orange powder

Solubility:
DMSO

Storage and Stability:
Store at -20°C. For maximum recovery of product, centrifuge the original vial prior to removing the cap.