Invitrogen™ Avidin Protein, HRP

Description

Avidin from chicken egg whites is a glycoprotein that effectively binds biotin, a tag that is frequently used to tag antibodies and other probes for immunodetection methods. This protein contains four identical subunits having a combined molecular mass of 67,000 to 68,000 daltons. Each subunit binds one molecule of biotin, and studies have shown that tryptophan and lysine are involved in the binding site for biotin. The sequencing of the subunit indicates it consists of 128 amino acids. Avidin has an isoelectric point of 10-10.5 and is very soluble in water and salt solutions. Avidin is stable over a wide range of pH values and temperatures. Extensive chemical modification has little effect on the activity of avidin, making it useful for detection and protein purification. Pure avidin is a key component in certain immunohistochemistry (IHC) methods. Alkaline phosphatase (AP) and horseradish peroxidase (HRP) conjugates of avidin are useful for Western blotting or ELISA detection with appropriate enzyme substrates.
Cross Reactivity: Bacteria, Tag
Formulation: 2mg purified protein (6.4mg/mL) in PBS and no preservative; pH 6.8
Molar Ratio of Active Conjugate: 1 mole HRP/mole Avidin Avidin Specific Activity: 8 ug Biotin bound/mg protein Peroxidase Activity: 182 units/mg protein; one unit is defined as the amount of protein required to form 1.0 umole of purpurogallin from pyrogallin in 20 seconds at 20°C in the following solution: 8 mM hydrogen peroxide, 14 mM potassium phosphate, 0.5% pyrogallol, pH 6.0. Product # 21123 is recommended for use in ELISA , FACS, Immunohistochemistry and Western blot applications. Restoration and storage: store at 4°C until opened. Restore with 0.4 ml of distilled water or buffer of your choice. For long-term storage, freeze undiluted product in small aliquots. Avoid repeated freezing and thawing. Note: Do not use Sodium Azide with this product since it is an inhibitor of horseradish peroxidase. This product has been overfilled to 2.2 mg to ensure total recovery of stated material.