An analytical affinity chromatography assay has been developed for the investigation of the dissociation of antigen-antibody complexes. Albumin-coupled Sepharose 4B and anti-albumin has been used as a model system. At extremely low or high pH, in the presence of highly concentrated chaotropic ions at pH 7 or by elution with 100% ethylene glycol after pretreating with high pH buffer, most of the bondings could be ruptured. The latter two-step desorption procedure provides recovery of intact antibody with high yield. The technique was also utilized for the preparation of antibody against human growth hormone.