Protein A isolated from Staphylococcus aureus, is attached through a stable linkage to heat stable, crosslinked 4% agarose gel beads. The method of attachment allows for maximum immunoglobulin binding capacity and ease of elution. Agarose Protein A (SP-0050) can be used for immunoglobulin purification, immunoprecipitation of antigens, or other applications involving specific immunoglobulin binding. Protein concentration is 2 mg/ml of settled agarose beads and is supplied as a 1:1 suspension in buffer. The binding capacity exceeds 10 mg Human IgG per ml of settled beads.