Purity >95% as determined by SDS-PAGE. Basic fibroblast growth factor (bFGF), also known as FGF2, is expressed by endothelial cells and is a mediator of angiogenesis. bFGF also has cardioprotective functions during heart injury. The application of bFGF is a critical component for embryonic stem cell culture systems and is necessary for maintaining cells in an undifferentiated state. Degredation of the full length bFGF N-terminus results in a truncated bFGF147aa protein, when the protein is isolated from biological sources. The N-terminus extensions influence the localization of bFGF within the cell, but do not affect the biological activity of bFGF. Therefore, there are no detectable differences in biological activity between the full length bFGF-154aa and the truncated bFGF-147aa recombinant proteins.