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.
Chicken Egg White
UltraAvidin™ is a lyophilized powder containing <2% salts and < 2% Moisture. Therefore, the UltraAvidin concentration should be determined by measuring the absobance at A280 nm and calculated using the extinction coefficient.
Chicken Egg White
Reconstitute in highly pure deionized water to 1-15 mg/ml. If buffering is required, add sufficient stock solution of 10-20X phosphate buffered saline (PBS) to bring the final concentration to 1X PBS. Do not reconstitute directly in PBS.
>95% by SDS Page
Storage and Stability
The lyophilized UltraAvidin™ should be stored desiccated at -20°C. Store reconstituted UltraAvidin™ at -20°C in working aliquots. Avoid repeated freezing and thawing.
11-17 µg biotin bound/mg UltraAvidin™
6.3 +/- 0.3
1.66 (mg/ml)-1 cm-1. A 1.0 mg/ml solution of pure UltraAvidin™ will have an absorbance at A280 nm of 1.66 with a 1 cm light path.
Country of Origin
1. Alon, R., Bayer, E. A., and Wilchek, M.1 (1990)"Streptavidin Contains An RYD Sequence Which Mimics The RGD Receptor Domain Of Fibronectin" Biochemical and Biophysical Research Communications 170:1236-1241
Products are for research use only. Not for use in diagnostic or therapeutic procedures.
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