Protein A, S. aureus, Cowan Strain (Biotin)

Blue Ice

Supplied as a powder in 10mM HEPES, pH 8.0, 0.15M sodium chloride. Labeled with Biotin. Reconstitute in 500ul of sterile ddH2O, 0.1% BSA

Protein A, isolated from a special strain of Staphylococcus aureus, is a 41, 000D protein capable of binding to the Fc portion of immunoglobulin. This interaction is not species specific, as Protein A has been shown to bind IgG from a variety of species. The binding was thought to be restricted to IgG, but subsequent studies have demonstrated that Protein A can interact with IgA, IgM and subclasses of IgG from different species. Biotinylated Protein A is a useful reagent for detecting or localizing immunoglobulins on cell surfaces or in tissue sections. Used with the appropriate Avidin D conjugate, immunoglobulins can be studied at the fluorescent or electron microscopic level. Biotinylated Protein A can also be employed for the detection of positive clones in monoclonal antibody production by using Avidin D conjugated with peroxidase or other marker enzymes. Used in many systems as a substitute for a biotinylated second antibody. Because Biotinylated Protein A may produce a high background by binding to endogenous immunoglobulin in the tissue, or it may not bind to the species or class of pri-mary antibody employed, we recommend using biotinylated anti-immunoglobulins for routine immunohistochemical staining.

Solid-phase assay of immunoglobulin reactivity normalized to rabbit IgG

Protein Reactivity:
Human IgG: 100%
Bovine, feline, canine, goat, guinea pig, equine, murine, sheep, swine and Rhesus monkey IgG: 50%
Rat IgG: 25%
Chicken and Hamster IgG: 1%

Storage and Stability:
Lyophilized and reconstituted products are stable for 12 months after receipt at -20°C. Reconstitute with sterile ddH2O. Aliquot to avoid repeated freezing and thawing. Store at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.