mFluor™ Violet 450-PEG4-Biotin Conjugate contains mFluor™ Violet 450 fluorophore that is well excited by the common 405 nm violet laser. It demonstrates excellent avidin binding and strong blue fluorescence. Its avidin-binding properties is similar to the native biotin in terms of high affinity, fast association, and non-cooperative binding to avidin and streptavidin tetramers. mFluor™ Violet 450 biotin conjugate can be used for detecting and quantifying biotin binding sites of avidin, streptavidin or neutravidin. It is a water-soluble reagent and has pH independent fluorescence from pH 4 to pH 10. The flexible PEG4 spacer between biotin moiety and fluorescent tag minimizes the steric hindrance involved in binding to avidin, streptavidin or neutravidin.