The RK13 cell line was initiated from the kidney tissue of a 5-week-old rabbit (Oryctolagus cuniculus). The cells exhibit typical epithelial characteristics and are positive for keratin by immunoperoxidase staining.

In the mid-1990s, studies demonstrated that the RK13 cell line, as well as a wide array of other cell lines originating from various species, had been contaminated with the bovine viral diarrhea virus (BVDV). RK13 cells are commonly used to isolate viruses and as transfection hosts. The cells are known to be susceptible to herpes simplex, rabbitpox, myxoma, pseudorabies virus, B virus, vaccinia, rubellavirus, and simian adenoviruses.

The kidneys are organs specialized for filtration of the blood. Similar to the filtration system of a car, if the kidneys become clogged or overworked, a multitude of problems may occur. For instance, renal failure, diabetes, liver malfunction, and many other disorders may occur if toxins are allowed to build up in the blood because the kidneys are not able to work properly. In rabbits, such kidney-related ailments are not uncommon, the many toxins present in the environment, most of which have been introduced by humans, causing serious and widespread health problems for the small animals. Kidney problems in rabbits may also occur due to other causes, such as parasitic infection. Notably, the rabbit parasite Encephalitozoon cuniculi is only able to replicate in the kidneys and the host is only contagious when it is present in the organs. In the kidneys, E. cuniculi typically causes scarring and pitting, but when the parasite is passed through the blood to other areas of the body even more serious damage may occur, particularly paralysis related to infection of neural tissues.

The culture of rabbit kidney epithelial cells presented in the digital image above was labeled for the intracellular mitochondrial network with MitoTracker Red CMXRos. DNA in the cell nucleus was counterstained with Hoechst 33342. Images were recorded in grayscale with a 12-bit digital camera coupled to either a Nikon E-600 or 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.

Using Fluorescent Proteins to Probe the Endoplasmic Reticulum in Epithelial RK13 Cells - The rabbit kidney epithelial (RK13) cell culture featured in this section was transfected with a recombinant plasmid vector containing a chimeric fusion gene product of DsRed fluorescent protein targeting the endoplasmic reticulum. In addition, the cells were treated with the popular nuclear counterstain Hoechst 33342.