Avidin Polyclonal Antibody, Biotin, Invitrogen™

Description

Product # 31850 is capable of binding to Avidin D by two mechanisms, either through the antigen binding sites in the Fab portion of the antibody or through multiple biotin residues covalently attached to the protein. The measured activity of the biotinylated antibody is 99% by a solid phase IgG binding assay. Reconstitute using 1 mL of distilled water; product may be stored for several weeks as an undiluted liquid. After dilution, do not use for more than one day. After one year, the reconstituted liquid product should be stored frozen in small undiluted aliquots, avoiding freeze/thaw cycles.

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.