Page 3 Angiogenesis The process of new blood vessel formation This assay on matrigel measures both the migrational and organization of endothelial cell on a surface that facilities the initial angiogenic event. While matrigel is not required for the formation of the network structure, it greatly facilitates the process, maybe, in part due to the high degree of glycosylation of laminin which is the major component of matrigel. Inhibitors of this process are quite easily identified as seen in the image below.   Umbilical Artery Outgrowth Arteries from fresh human umbilical cords were dissected and imbedded in a fibrin gel. Endothelial cells were observed to migrate from the ends of the arteries and in some cases organize into tubules. An angiogenic inhibitor can prevent any outgrowth into the gel. This assay is conducted for three weeks with initial outgrowth seen after 3-4 days. Typical outgrowth and inhibition is shown below.