In biological techniques and sciences, polysorbate 20 has a broad range of applications. For example, it is used: • as a washing agent in
immunoassays, such as
Western blots and
ELISAs. It helps to prevent non-specific antibody binding. In this major application, it is dissolved in
Tris-buffered saline or
phosphate buffered saline at dilutions of 0.05% to 0.5% v/v. These buffers are used for washes between each immunoreaction, to remove unbound immunologicals, and eventually for incubating solutions of immunoreagents (labeled antibodies) to reduce nonspecific background. • to saturate binding sites on surfaces (i.e., to coat polystyrene microplates, generally combined with proteins such as BSA). • to stabilize proteins
purified protein derivative (PPD) solution used in skin testing for
tuberculosis exposure • as a solubilizing agent of
membrane proteins • for
lysing mammalian cells, at a concentration of 0.05% to 0.5% v/v, generally combined with other detergents, salts and additives. ==Pharmaceutical applications==