title: The rapid isolation of ribonuclease-free immunoglobulin G by protein A-sepharose affinity chromatography.
abstract: A rapid method is described for the simultaneous removal of contaminant ribonuclease activity and isolation of immunoglobulin G from fractionated or whole serum using insolubilized protein A. Protein A, isolated from the Cowan I strain of Staphylococcus aureus, was covalently attached to Sepharose CL-4B resin and used as a specific affinity absorbent for immunoglobulin G. Affinity column-purified immunoglobulin G preparations were examined for the presence of contaminating serum proteins, retention of antibody activity, and retention of antigenic properties. Following chromatography on protein A-Sepharose, immunoglobulin G preparations were devoid of contaminating serum proteins, in particular ribonuclease activity, that are not normally removed using conventional techniques of salt precipitation in combination with ion-exchange chromatography. There was no significant alteration of either antibody activity or antigenic properties of protein A-Sepharose purified immunoglobulin G.
mesh_terms: D000818:Animals; D002499:Centrifugation, Density Gradient; D011232:Chemical Precipitation; D002846:Chromatography, Affinity; D002852:Chromatography, Ion Exchange; D004591:Electrophoresis, Polyacrylamide Gel; D007074:Immunoglobulin G / Q000302:isolation & purification*; D011134:Polysaccharides / Q000494:pharmacology*; D011817:Rabbits; D012260:Ribonucleases; D012492:Salts; D012685:Sepharose / Q000494:pharmacology*; D012710:Serum Albumin, Bovine / Q000276:immunology; D013205:Staphylococcal Protein A / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D007074:Immunoglobulin G; D011134:Polysaccharides; D012492:Salts; D013205:Staphylococcal Protein A; D012710:Serum Albumin, Bovine; D012685:Sepharose; D012260:Ribonucleases