UltraAvidin™ is Leinco Technologies' trademark for a uniquely modified form of avidin which is isolated from chicken egg whites. With a molecular weight of 60,000, there are four identical subunits each capable of binding one molecule of biotin. UltraAvidin from Leinco Technologies has been de-glycosylated to prevent carbohydrate moieties from adhering to lectin-like receptors on the surface of cells, thus eliminating the possibility of false positives. Unlike native avidin, UltraAvidin has a near neutral pI which prevents electrostatic interactions with negatively charged serum or membrane proteins. Recent studies have identified a universal recognition sequence in streptavidin which is similar to that found in several adhesion receptors.(1) It is a tripeptide sequence Arg-Tyr-Asp (RYD) which mimics the Arg-Gly-Asp (RGD) binding sequence of fibronectin. Strong interactions have been shown with streptavidin and cell surface molecules. This universal recognition sequence is not present in UltraAvidin. UltraAvidin may not significantly increase sensitivity in all research systems but will help assure specificity.
This Fluorescein (FITC) conjugate is formulated in 0.01 M phosphate buffered saline (150 mM NaCl) PBS pH 7.4, 1% BSA and 0.09% sodium azide as a preservative.
UltraAvidin-FITC has been tested by flow cytometric analysis to detect biotinylated primary antibodies. A woring dilution ≤ 0.125 μg per 100 μl blood (or per 1 million cells in 100 μl total staining volume) is suitable for most applications. However, each investigator should determine their own optimal working dilution for each specific research application.
Storage and Stability
This Fluorescein conjugate is stable when stored at 2-8°C. Do not freeze.
Country of Origin
Next Day Ambient
References & Citations
1. Wilchek, M. et al. (1990) Biochem Biophys Res Commun. 170(3):1236-41.
2. Sullivan, W. et al. (1996) Genetics. 143(4):1629-42.
IMPORTANT Use lot specific datasheet for all technical information pertaining to this recombinant protein.