Fig. 2. Staurosporine-induced E-lam formation in HaCaT keratinocytes. (A) The morphology of HaCaT cells spreading on fibronectin in absence (a) or in presence (b) of staurosporine as visualized by scanning electron microscopy. Extended lamellipodia are marked with arrows and filopodia with arrowheads. Scale bar: 10 µm. Equivalent phase contrast pictures (insets) from crystal violet stained cells were taken using 20x objective. (B) The cells were allowed to spread on fibronectin for 60 minutes in presence of staurosporine (0-100 nM). The cells were fixed and four representative fields in triplicate wells were examined by phase-contrast microscopy using a 20x objective (n=12). The percentage of cells that were spread or forming E-lams out of the total cell number within each field was calculated (mean±s.d.). (C) The cells were allowed to spread on fibronectin for 2 hours and then treated with 50 nM staurosporine for 1 hour or left untreated. For comparison, some of the cells were treated with staurosporine for 3 hours. The cells were fixed, and the percentage of cells that were spread or forming E-lams of the total cell number was calculated as in B (mean±s.d., n=12).