Abstract: Acidic fibroblast growth factor (aFGF) is isolated and purified from human brain tissue. The distinctive and complete amino acid sequences of both bovine and human aFGFs are determined and herein disclosed. Unique genes coding for these disclosed amino acid sequences are constructed. The bovine gene is derived from reverse translation of the aFGF amino acid sequence with unique restriction sites included while the human gene is derived by specific point mutations of the bovine gene. Each gene construct is inserted into an expression vector which is used to transform an appropriate host. The transformed host cells produce recombinant aFGF (r-aFGF), human or bovine, which is purified and has activity equivalent to the native protein. Both recombinant and purified brain-derived human and bovine aFGF are active mitogens for mesoderm and neuroectoderm-derived cells in culture, and promote wound healing of soft tissue, cartilaginous tissue and musculo-skeletal tissue.