Chronic wounds are "any interruption on the continuity of the body's tissue that requires a prolonged time to heal, does not heal, or recurs" (Wysocki, 1996). Venous leg ulcers, pressure sores, ischemic ulcers, and diabetic foot ulcers are examples of chronic wounds. These kinds of wounds affect over 4 million Americans each year and cost over $9 billion to treat. The pathophysiology of these wounds is not well understood and therapies directed at healing these wounds are not always successful for unknown reasons. To better understand the pathophysiology of these wounds we propose to collect blood by venipuncture from healthy volunteers. Blood will be used to prepare blood and plasma derived serum for use in an in vitro wound healing model and Boyden chamber assays to study cell migration, adhesion, genetic expression, expression of cell surface receptors, and protein expression to construct a profile of various healing processes. This baseline data will be used for studying the effect of acute and chronic wound fluids on cell migration, adhesion, genetic expression, expression of cell surface receptor and protein expression in an in vitro wound model (protocols to be submitted for each patient population).