Cy7 biotin conjugate

Correction Factor (260 nm): 0.05. Correction Factor (280 nm): 0.036. Correction Factor (482 nm): 0.0005. Correction Factor (565 nm): 0.0193. Correction Factor (650 nm): 0.165. Extinction coefficient (cm -1 M -1): 250000. Excitation (nm): 756. Emission (nm): 779. Cy7 biotin conjugate demonstrates excellent avidin binding and strong NIR fluorescence. It has avidin-binding properties similar to native biotin in terms of high affinity, fast association, and non-cooperative binding to avidin and streptavidin tetramers. Cy7 Biotin can be used for detecting and quantifying biotin binding sites of avidin, streptavidin or neutravidin. This reagent overcomes major shortcomings of commonly used Biotin-4-fluorescein, e.g., poor solubility in aqueous media and pH dependent absorbance and short wavelength emission. Cy7 Biotin is a water-soluble reagent and its near infrared fluorescence is pH independent from pH 4 to pH 10. A flexible PEG spacer between biotin moiety and fluorescent tag minimizes the steric hindrance involved in binding to avidin, streptavidin or neutravidin.