The present invention relates to novel fluorescent dyes, novel fluorogenic and fluorescent reporter molecules and new enzyme assay processes that can be used to detect the activity of caspases and other enzymes involved in apoptosis in whole cells, cell lines and tissue samples derived from any living organism or organ. A visual display system includes a projector having a light source with a fixed spectral output, a display screen receiving the output of the projector and emitting a diffused output, and a color correction contrast enhancement filter positioned between the diffusing screen and a viewer. The edge may present a profile and may present a closed section. The separator roller also includes a recoil mechanism.