Wound closure following injury to the skin is a complex process involving both dermal contraction and keratinocyte migration. Murine models of wound healing are potentially useful because of the ability to determine protein function through gene manipulation. Owing to the dominant role of dermal contraction, the technical difficulties in preparing the wound site for morphologic studies, and the postnatal phenotypes altering the properties of transgenic skin, there are difficulties in assessing the epithelial contribution to wound closure in mouse skin. We describe a simple ex vivo assay utilizing explant culture that enables a quantitative assessment of the potential of mouse keratinocytes for wound epithelialization. In this assay, the behavior and properties of skin keratinocytes mimic well those that occur at the edge of skin wounds in situ, including a dependence upon connective tissue element(s), proliferation, and migration. The epithelial cell outgrowths emerging from skin explants can be studied in real-time or examined at specific time-points for markers of interest in the epithelialization process. The assay is quantitative and can successfully detect increases or decreases in epithelialization potential, and can be useful in the characterization of transgenic mouse models.
