Extrusion of a caspase stained cell after treatment with LYHY. Mature Eph4 monolayers grown on glass slides were treated with LYHY peptide at 350 μM for 6 hours. They were stained live during the 6th hour of treatment with carboxyfluorescein-LETD-fluoromethyl ketone for activated caspase 8 as described in Materials and Methods. After fixation monolayers were stained for occludin and nuclei. An extruding cell stained for caspase 8 shows a narrow extrusion "tail" and has a slightly pyknotic nucleus. Surrounding cells have closed the gap around the extruding cell as shown by occludin staining. Occludin is no longer visible in the extruding cell. Black and while images show separate channels for nuclei, caspase 8 and occludin staining. The merged colored image is on the left.