title: Thermal and vortical stability of purified human fibroblast interferon.
abstract: The loss of biological activity upon heating or agitation of human interferons is markedly altered by changing their aqueous environment. Low pH significantly stabilizes liquid fibroblast interferon at 68 degrees C and 37 degrees C whereas chaotropic salts stabilize at 68 degrees C but not at 37 degrees C; this anomalous result may be due to reactivation of biological activity at the higher temperature. The concentration of extraneous proteins influences the apparent thermal stability at any temperature and pH; thus, interferon was not stable even at low pH at protein concentrations less than 5 microgram/ml. Solutions of partially purified fibroblast interferon can be inactivated by mechanical stress; the addition of proteins or nonionic detergents prevents such inactivation. Freeze-dried preparations show the greatest thermal stability. The use of high-temperature, accelerated storage tests makes it possible to predict the shelf-life of freeze-dried interferon.
mesh_terms: D004355:Drug Stability; D005347:Fibroblasts / Q000276:immunology*; D005612:Freeze Drying; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007372:Interferons / Q000302:isolation & purification*; D013696:Temperature
chemical_list: D007372:Interferons