Quick purification of recombinant human truncated tau proteins for immunoanalysis

A simple and rapid purification method is described which exploits the heat stability of human tau (tau) protein to prepare truncated forms of this protein derived from bacteria. Bacterial cells expressing tau fragments were pelleted, resuspended in phosphate buffered saline and boiled for 5 min. After centrifugation the supernatant containing thermostable tau was filtered (0.45 microns) and used for immunoanalysis with monoclonal antibodies. The purified tau fragments exhibited identical antigenic properties as fragments isolated by a conventional procedure, based on ion exchange chromatography on phosphocellulose. In contrast to the conventional approach, our method is less complicated, cheaper and significantly reduces the time required for isolation of the recombinant tau fragments.