A transgenic mouse, in which the regulatory elements of the stem cell marker, nestin drive green fluorescent protein (ND-GFP), expresses GFP in nascent blood vessels. Red fluorescent protein (RFP)-expressing tumors transplanted to nestin-GFP mice enable specific visualization of nascent vessels in the growing tumors. The ND-GFP mouse was also utilized to develop a rapid in vivo/ex vivo fluorescent angiogenesis assay by implanting Gelfoam� , a surgical sponge derived from pigskin, which was rapidly vascularized by fluorescent nascent blood vessels. Angiogenesis could be imaged and quantified when stimulated or inhibited by specific compounds in both tumors and Gelfoam� . These fluorescent models can be used to study the early events of angiogenesis and to quantitatively determine efficacy of antiangiogenesis compounds.
