Current Applications of Staphylococcal Protein A in Biotechnology and Biomedicine: A Comprehensive Review.

Protein A (SpA), a cell wall-associated protein of Staphylococcus aureus, is an immunoglobulin (Ig) binding molecule with high affinity to the Fc moiety of IgG. It can help S. aureus for effective shielding from recognition and opsonization by immune cells, thereby promoting bacterial immune evasion. Since its recognition in the early 1980s, diverse applications have been developed across biotechnology, medicine, and biochemical research, using both native and recombinant SpA variants produced in various host cells. This review provides a comprehensive overview of the major applications of SpA, with an emphasis on techniques that progressed to commercially available tools/platforms. These applications are based on its Ig-binding capability, including purification of monoclonal antibodies in biopharmaceutical manufacturing, selective isolation of antibodies in diagnostic workflows, integration into serological assays or biosensor systems, and use as a fusion partner/tag for capturing recombinant proteins.