Figure 3

HMGB1 epithelial staining in unburned vs. burned ex vivo skin. Immunohistochemical staining of HMGB1—a marker for tissue viability. The negative control incubated without the primary antibody shows no HMGB1 background signal (a). In unburned tissue HMGB1 is localized to the nucleus (b). In burned tissue HMGB1 staining is diffuse ((c), black arrows) or not present anymore (d), showing release of HMGB1 due to cell death. Samples (non-debrided, non-infected, no neutrophil supplementation) were fixed on day 6 after burning. For number of skin donors and technical replicates see Table S1. Representative images are shown.