It is now widely accepted that much of the dynamic function of cells and tissues is regulated from outside the cell by the extracellular matrix. In ad- tion to its conventional role in providing a scaffold for building tissues, the extracellular matrix acts as a directional highway for cellular movement and provides instructional information for promoting survival, proliferation, and differentiation. Indeed, the extracellular matrix is beginning to take a starring role in the choreography of cell and tissue function. The diverse roles of the extracellular matrix are reflected in its highly complicated structure, consisting of an ever increasing number of components. Yet the mechanisms of extracellular matrix assembly and how they influences cell behavior are only just beginning to be understood. In order to solve these problems new methodologies are, of necessity, being developed. Many of these technologies are highly sophisticated and are currently available only in a ha- ful of laboratories. However, we believe that they can readily be transported and established by other researchers. Thus, the purpose of Extracellular Matrix Protocols is to present some of these complicated techniques in a style that is relatively easy to reproduce.