title: Three step purification of C1q by DNA precipitation, ion exchange and lectin affinity chromatography.
abstract: The difficulties associated with the isolation of pure C1q in sufficient amounts are reflected by the substantial number of isolation procedures, which are being published. The two major problems are a low yield and contaminating immunoglobulins. In addition, some isolation protocols appear to produce C1q contaminated with an inhibitor (C1q-INH). The present isolation protocol involves precipitation of C1q by DNA, chromatography using Sephadex QAE A 50 followed by Con A affinity chromatography. By this combination of purification steps maximal advantage was taken of the cationic properties and high carbohydrate content of the C1q molecule. The yield was 1-2 mg C1q per 100 ml serum. The isolated C1q was free of any demonstrable contaminants as demonstrated by Ouchterlony double diffusion and polyacrylamide gel electrophoresis.
mesh_terms: D002846:Chromatography, Affinity; D002852:Chromatography, Ion Exchange; D003166:Complement Activating Enzymes / Q000302:isolation & purification*; D015922:Complement C1q; D004247:DNA; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007122:Immunoelectrophoresis; D008722:Methods
chemical_list: D015922:Complement C1q; D004247:DNA; D003166:Complement Activating Enzymes