![](https://www.microscopyu.com/assets/gallery-images/Filter-Combos/Red/cy5yhq-ptk2-keratin-cy5.jpg)
Rat Kangaroo Cytokeratin Intermediate Filaments with Cy5
Cy5 HYQ Bandpass Emission (Wide Bandwidth Excitation) Red Set
Fluorescence emission intensity from a culture of rat kangaroo kidney epithelial cells (PtK2 line) that were immunofluorescently labeled with primary anti-cytokeratin (pan) mouse monoclonal antibodies followed by goat anti-mouse Fab fragments conjugated to Cy5. The visible light absorption maximum of Cy5 is 649 nanometers and the emission maximum occurs at 670 nanometers. The image was captured in 12-bit grayscale mode, but subsequently pseudocolored by converting to the RGB color palette and setting the green and blue channels to zero (to produce a red image). Note the bright fluorescence intensity exhibited by the intermediate filament network, which extends throughout the cytoplasm in these epithelial cells.