Rat Kangaroo Cellular Cytokeratin Intermediate Filament Network with Cy3

Fluorescence emission intensity from a culture of rat kangaroo kidney epithelial cells (PtK2line) that were immunofluorescently labeled with primary anti-cytokeratin (pan) mouse monoclonal antibodies followed by goat anti-mouse Fab fragments conjugated to Cy3. The visible light absorption maximum of Cy3 is 552 nanometers and the emission maximum occurs at 570 nanometers. In addition, the specimen was stained with DAPI (targeting DNA in the nucleus; ultraviolet excitation and blue emission), but this fluorophore is not imaged with the Nikon TRITC HYQ filter combination. Note the bright fluorescence intensity exhibited by the cytokeratin intermediate filament network, which extends throughout the cytoplasm in these epithelial cells.