FGF-basic is one of 23 known members of the FGF family. Proteins of this family play a central role during prenatal development, postnatal growth and regeneration of a variety of tissues, by promoting cellular proliferation and differentiation. FGF-basic exerts proliferative activity towards a wide range of cell types and consequently is used as a vital component in numerous cell culture media formulations, including stem cell media. FGF-basic loses its activity over time in solution at physiological temperatures and needs to be resupplemented periodically to maintain its performance. As a result of selected amino acid substitutions, Heat Stable FGF-basic retains full biological activity and also maintains full activity over extended periods of time in solution at 37°C. These properties make Heat Stable FGF-basic a superior choice for use in cell culture media applications. Heat Stable Recombinant Human FGF-basic is a 17.2 kDa protein consisting of 154 amino acids.