purity of an antibody solution is to run a portion of the sample on an SDS-polyacrylamide gel.The gel can be stained with Coomassie blue (sensitivity 0.1-0.5 ug/band) or silver stain (1-10 ng).The following are other procedures that can be used to check the purity of an antibody:polyacrylamide disc electrophoresis,all types of immunoelectrophoresis,isoelectric focusing, capillary electrophoresis,ultracentrifugation,and various types of high performance liquid chromatography HPLC.Purity is generally determined by more than one technique. Quantitation If the antibody is pure,you can measure the total protein concentration.A convenient method is UV absorbance.The amount of antibody can be determined by an absorbance measurement at 280 nm (1 absorbance unit equal 0.75 mg/ml of purified antibody).If the antibody is not yet pure samples can be quantified by various immunological procedures.Figures 12 -16 are procedures that can be used to quantitatively determine the concentration of antibody in the presence of other proteins.By modifying these same procedures the class or subclass of antibodies can be measured. Antigen binding activity Antibody activity is measuredpurity of an antibody solution is to run a portion of the sample on an SDS-polyacrylamide gel. The gel can be stained with Coomassie blue (sensitivity 0.1-0.5 ug/band) or silver stain (1-10 ng). The following are other procedures that can be used to check the purity of an antibody: polyacrylamide disc electrophoresis, all types of immunoelectrophoresis, isoelectric focusing, capillary electrophoresis, ultracentrifugation, and various types of high performance liquid chromatography HPLC. Purity is generally determined by more than one technique. Quantitation If the antibody is pure, you can measure the total protein concentration. A convenient method is UV absorbance. The amount of antibody can be determined by an absorbance measurement at 280 nm (1 absorbance unit equal 0.75 mg/ml of purified antibody). If the antibody is not yet pure samples can be quantified by various immunological procedures. Figures 12 -16 are procedures that can be used to quantitatively determine the concentration of antibody in the presence of other proteins. By modifying these same procedures the class or subclass of antibodies can be measured. Antigen binding activity Antibody activity is measured