Description
GenScript Protein A Resin is an affinity
chromatography medium designed for easy, one-step purification of classes, subclasses
and fragments of immunoglobulins from biological fluids and from cell culture
media. Protein A Resin can also be used for immunoprecipitation of
proteins, protein complexes or antigens. The recombinant protein A ligand is
coupled to 4%
agarose. The coupling is optimized to give high binding capacity for
immunoglobulins. The static binding
capacity of Protein A Resin is greater than 20 mg human IgG/ml settled resin.
The binding capacity will
vary depending on several factors such as target antibody, flow rate etc. Table
1 lists the characteristics of Protein A Resin.
Protein A, a bacterial cell wall protein isolated
from Staphylococcus
aureus,
binds to mammalian IgGs mainly through Fc regions. Native
protein A has five IgG binding domains and many other domains with unknown
functions. Recombinant protein A contains five high
affinity IgG binding domains with other non-essential domains removed to reduce nonspecific binding. Since only the Fc region
is involved in binding, the Fab region is available for binding antigens.