The search for rapid and reproduciblein vivoangiogenesis and antiangiogenesis assays is an area of intense interest. These types of assays are extremely useful in testing putative drugs and biological agents and for the comparison and enhancement ofin vitrotests. The Matrigel plug assay is one such assay and has proved to be a relatively quick and easy method to evaluate both angiogenic and antiangiogenic compoundsin vivo. Initial indications of the levels of activity of strong angiogenic or antiangiogenic compounds can be visually assessed even as the plugs come out of the mouse because there are color differences in the plugs compared to the controls. Further quantitation is then needed to determine levels of angiogenic/antiangiogenic activity, and this can be performed using a variety of methods. This chapter presents an overview of the basic methods used to set up both angiogenic and antiangiogenic assays, discusses factors influencing variability, and discusses the methods for quantitating the plugs obtained. The Matrigel plug assay provides another useful tool in angiogenesis research.
