The kidney of a rat only exhibits a single lobe, but those of larger animals, such as sheep and humans, are generally multilobar. Each lobe is comprised of a renal pyramid and its overlying cortical tissue. During the development of the human fetus, the lobes of the kidneys exhibit deep crevices, but these usually disappear completely by the time adulthood is reached. Occasionally, however, clefts are retained in the kidneys throughout life resulting in a state that is typically called lobated kidney. A variety of other malformations may afflict the kidneys as well. Polycystic kidney disease, for instance, is characterized by the development of cysts in and on the organs.

The culture of Madin-Darby ovine kidney (MDOK) cells presented in the digital image above was labeled with MitoTracker Red CMXRos and Alexa Fluor 488 conjugated to phalloidin, targeting the mitochondrial network and filamentous actin, respectively. The culture was counterstained for DNA in the cell nucleus with Hoechst 33258. Images were recorded in grayscale with a QImaging Retiga Fast-EXi camera system coupled to an Olympus BX-51 microscope equipped with bandpass emission fluorescence filter optical blocks provided by Omega Optical. During the processing stage, individual image channels were pseudocolored with RGB values corresponding to each of the fluorophore emission spectral profiles.