The origin of protein A is from the bacteria Staphylococcus aureus. Protein A is capable of binding most classes and subclasses of immunoglobulins from Goat, Rabbit, Mouse and Human.

Adar’s Protein A beads are produced using a genetically engineered form of Protein A. Nonessential regions have been removed while leaving the immunoglobulins binding sites intact.

The recombinant Protein A has been immobilized to Sepharose beads using Adar Biotech's TargetLock chemistry, in order to create a superior product for the affinity purification and immunoprecipitation of various mammalian immunoglobulins. Protein A beads are routinely used for the isolation of IgG from several species of mammals.

The binding of Protein A to IgGs vary between animal species and between IgG subclasses within the same species. A major limitation of protein A lies with the weak binding it presents towards mouse IgG1-a common IgG subclass. Despite that, Protein A possesses useful properties that make it a popular choice for the isolation of most types of IgGs. Protein A binds IgGs through the Fc region of the molecule, leaving the Fab region available for binding the antigen. Protein A Beads are commomnly used for antibody purification and for the isolation of immune complexes by Immunoprecipitation (IP).

Protein A Beads Specifications

Matrix: Sepharose^TM CL-4B
Coupling method: TargetLock.
Protein A density: 2-4 mg/ml of resin
Binding capacity: ~4-8 mg rabbit IgG per ml of resin
Mean bead size: 40 -165 μm
Bead structure: Highly cross-linked spherical agarose, 4%
Max back pressure: 0.3 MPa, 3 bar
Max. flow rate: 4 ml/min/cm²
Recommended flow rate: 1-3 ml/min/cm²
Stability of the matrix: pH 2-11.
Storage: 4°C in PBS pH 7.4 added with NaN3 0.1% (w/v) as a preservative.