Vascular endothelial growth factor (VEGF) is homodimeric, heparin-binding glycoprotein involved in both angiogenesis and vasculogenesis. VEGF is expressed as multiple alternately spliced isoforms of VEGF121, 165, 189 and 206. VEGF binds to the receptor tyrosine kinases VEGF R1 (Flt-1) and VEGF R2 (KDR/Flk-1) to activate signal transduction and regulate both physiological and pathological angiogenesis. Sequence of amino acids: MGSSHHHHHH SSGLVPRGSH MAPMAEGGGQ NHHEVVKFMD VYQRSYCHPI ETLVDIFQEY PDEIEYIFKP SCVPLMRCGG CCNDEGLECV Molecular Weight: 16.3kD (142aa) Endotoxin: 1.0 EU/ug of protein (determined by LAL method) Storage and Stability: For long-term storage, aliquot and store at -20C. Aliquots are stable for at least 6 months at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.