Protein A-Agarose

Protein A-Agarose

I. Introduction

The Imgen BioSceinces’ Protein A-Agarose is 4% agarose beads that have been covalently coupled with recombinant protein A. It is a high quality immunoaffinity matrix for the purification of IgG fractions from biological fluids and from cell culture media. It is also an idea matrix for the isolation of antibody-antigen complexes by immunoprecipitation.

Native protein A, a bacterial cell wall protein from Staphylococcus aureus, binds specifically to the Fc region of immunoglobulin molecules of many mammalian species without disturbing their binding of antigen. A native protein A has five IgG binding domains. The recombinant protein A, used to produce Imgen BioSceinces’ Protein A-Agarose, has an exact amino acid copy of the native protein A from S. aureus, but expressed in and purified from E. coli. The purified recombinant protein A functions same as its native form, but with low levels of endotoxin contamination.

II. Features

1. High IgG binding capacity

2. Stable affinity medium

3. Milder elution condition than protein G resin

4. Resin is reusable up to 10 - 20 times

III. Characteristics

The matrix is a 4% agarose beads that have been covalently coupled with recombinant protein A by a cyanogen bromide method. The swollen agarose medium has approximately 6 mg of recombinant protein A/ml of drained resin. It’s total binding capacity for human IgG is about 25 -30 mg/ml of drained resin. It has high excellent chromatographic and immunoaffinity isolation qualities in high binding capacity, low leakage, and stable affinity medium. It withstands a wide range of pH, and many common denaturing reagents such as 4 M urea, 4 M thiourea and 6 M guanidine hydrochloride. The product characteristics are summarized in Table 1.

Table 1. Technical Specifications

Ligand Recombinant protein A (E. coli)
Ligand coupling Cyanogen bromide covalently coupling
Ligand density 6 mg recombinant protein A/ml resin
Matrix 4% agarose beads
Average beads size 90 μm (50 – 150 μm)
Binding capacity ≥25 mg human IgG/ml medium
pH stability 2 - 14 (short term); 3-12 (long term)
Flow rate 1 - 4 ml/min


Supplied as 50% aqueous suspension (e.g., 5 ml of settled resin is equivalent to 10 ml of 50% slurry) in buffer containing 20% ethanol, 20 mM sodium phosphate pH 7.4, 0.15 M NaCl, and 0.02% NaN3 (w/v). Product is shipped at ambient temperature.


+4°C to +8°C. Do not freeze.


Fig. 1. (right) Comparison of SDS-PAGE of purified antibodies from normal human serum by chromatography between with Imgen BioSciences’ Protein A-Agarose and with a leading competitor’s.

Lane 1:     Molecular weight marker
Lane 2:     Blank
Lane 3:     Loaded sample
Lane 4:     Flow through
Lane 5:     Elute
Lane 6:     Blank
Lane 7:     Loaded sample
Lane 8:     Flow through
Lane 9:     Elute

Order Information

Cat #Product NamePriceOrder
B-2001-25Protein A-Agarose, 25 ml settled resin (50 ml of 50% slurry)$750.00Order
B-2001-5Protein A-Agarose, 5 ml settled resin (10 ml of 50% slurry)$185.00Order