Recombinant Protein G is a genetically engineered form of Protein-G. Non-essential regions have been removed while leaving the IgG binding sites intact. Protein G has been extensively used for the isolation of IgG from several species of mammals. Although binding of Protein G to IgG's is not equivalent for all IgG subclasses, Protein-G possesses properties that have made it a popular choice for antibody isolation. Protein G binds immunoglobulins at the Fc region,leaving the Fab region free to bind the antigen. Hence, Protein G is extremely useful for isolating immune complexes.

Recombinant Protein G characteristics:

Source: recombinant protein, Molecular Weight 33 kd expressed in E. coli
Purity: > 90% by SDS-PAGE
Spectroscopic analysis: OD280nm/250nm=2.51
LAL Pyrogenicity: < 0.5 EU/mg Recombinant Protein G
Composition: Lyophilized white Powder. 10.6 mg Recombinant Protein G, 0.78 mg phosphate buffer salts.
Storage before reconstitution: Store at 4°C. Product is stable under these conditions for two years.
Reconstitution: Reconstitution per 10 mg vial with 0.48 mL of deionized water will give a solution containing 22.1 mg/ml Recombinant Protein G in 10 mM Phosphate buffer, pH 7.4
Storage after reconstitution: Store at 4°C in PBS pH 7.4 added with NaN₃ 0.1% (w/v) as a preservative. Product is stable under these conditions for 1 month. Alternatively, prepare small aliquots and store at -20^oC for up to two years. Avoid repeated freezing and thawing cycles.