Standardization and Calibration of Cytokine Immunoassays

Use of the appropriate quality of reagents is clearly important if immunoassays are to be optimised. Some reagents can affect the sensitivity and specificity of immunoassays and so quite different results may be obtained if reagents are not of comparable quality and purity. Particularly important is the quality of immunoglobulin reagents used in immuno-assays. It is necessary to purify the IgG fraction from antisera, ascitic fluid or hybridoma culture fluid e.g. for labelling with enzymes, radioisotopes or fluorochromes by ion-exchange chromatographic methods. Generally, it is advantageous to purify the antigen binding subpopulation from antibody containing fluids using affinity chromatography (1).