Chicken anti-protein A prevents Staphylococcus aureus protein A from binding to human and rabbit IgG in immunoassays and eliminates most false positive results.
This report demonstrates that chicken anti-protein A can prevent both soluble and surface-bound Staphylococcal protein A from binding to either human or rabbit IgG. In an ELISA assay, chicken anti-protein A prevented > 98% of the soluble protein A from binding to the human IgG-Fc coat. In a blotting assay, chicken anti-protein A prevented the membrane-bound protein A from interacting with the human IgG probe. When intact S. aureus (Cowan I strain) was bound to the surface of a microassay plate, chicken anti-protein A blocked > 98% of the cell wall protein A and permitted the probing of the surface components with human IgG. In another immunoassay, rabbit anti-enterotoxin A IgG was used to measure enterotoxin A concentrations in S. aureus culture medium supernatants after soluble protein A was blocked by chicken anti-protein A. Thus, the binding of chicken anti-protein A to protein A almost completely eliminates false positive results and permits the measurement of specific antibodies or antigens in a variety immunoassays where protein A is present.
Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235, USA.
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D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology / Q000378:metabolism*; D001667:Binding, Competitive / Q000276:immunology; D002645:Chickens; D005189:False Positive Reactions; D006801:Humans; D007118:Immunoassay / Q000379:methods; D007074:Immunoglobulin G / Q000276:immunology / Q000378:metabolism*; D011485:Protein Binding / Q000276:immunology; D011817:Rabbits; D013205:Staphylococcal Protein A / Q000276:immunology* / Q000378:metabolism*
D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D013205:Staphylococcal Protein A