Mitosis is a method of cell division that consists of a series of steps in which two identical daughter cells are produced from a single parent cell. Each of the daughter cells receives a full set of chromosomes indistinguishable from the chromosomes of the cell that produced them. Living PtK2 cells are popularly used to visualize the mitotic process because they contain a relatively few number of chromosomes, and these chromosomes are quite large in size. The cells are also particularly well suited for such a purpose because they remain relatively flat during mitosis, further increasing the ease with which the stages of nuclear division can be observed. Mitosis in PtK2 cells takes approximately 2 to 3.5 hours to complete in an environment maintained at 37 degrees Celsius.

In order to label the intermediate filaments in the PtK2 culture presented above, the fixed and permeabilized cells were blocked and treated with chicken anti-vimentin primary antibodies followed by goat anti-chicken secondary antibodies (IgG) conjugated to Alexa Fluor 568. Filamentous actin was visualized with phalloidin conjugated to Alexa Fluor 633, while the nuclei were counterstained with SYTOX Green. Images were recorded in grayscale with a 12-bit digital camera coupled to a Nikon Eclipse 80i microscope equipped with bandpass emission fluorescence filter optical blocks. During the processing stage, individual image channels were pseudocolored with RGB values corresponding to each of the fluorophore emission spectral profiles, with the exception of Alexa Fluor 633, which was pseudocolored magenta.