Biotin-4-fluorescein from Biotium, Inc.

Biotin-4-fluorescein (N-(5-aminopentyl)biotinamide, trifluoroacetic acid salt) has been reported to be a superior fluorescent biotin derivative for accurate measurement of avidin and streptavidin in crude biological samples. Binding of biotin to avidin and streptavidin is high affinity, fast and noncooperative. 

• λ_Ex/λ _Em = 494/523 nm
• Yellow solid soluble in DMSO, or pH>7 buffers
• Store at 4°C and protect from light
• C₃₃H₃₂N₄O₈S
• MW: 644.7