Cell death in the skin: how to study its quality and quantity?

The characterization of the quality and quantity of cell death has gained substantial interest over the past decades. More recently necroptosis as a programmed form of necrosis has been identified as an important additional form of cell death with relevance in the skin. Understanding how to assay cell death in specific is of critical importance for cancer research and treatment. Here we describe six different methods that can be used to assay cell viability and to study the quality or quantity of cultured human keratinocytes in vitro. These methods include crystal violet assay, hypodiploidy analysis, caspase-8 cleavage, release of HMGB1, annexin V/propidium iodide co-staining, and Hoechst/SYTOX green co-staining.