Presented below is a photomicrograph of tissue from a mouse kidney. This digital image was captured with the DXM 1200 ACT-1 control software in single-image acquisition mode utilizing DIC and fluoresence illumination.

The kidney is an organ that maintains water balance and expels metabolic wastes in vertebrates and some invertebrates. Primitive and embryonic kidneys have sets of specialized tubules that empty into two collecting ducts that pass urine into a primitive bladder. The more advanced mammalian kidney is a paired compact organ with functional units, called nephrons, that filter the blood, reabsorbing water and nutrients and secreting wastes, producing the final urine.

Mouse kidneys are located on the dorsal (upper) wall of the abdominal cavity and are securely held in place by fibrous capsules. Like other mammalian kidneys, the outer layer of the kidney is brownish red and granular in appearance, with a firm consistency. Mouse kidneys are similar to human kidneys, which is why they are often used to simulate human kidneys in scientific studies. Mice have played a significant role in experiments used to diagnose the possible cause and treatment of IgA nephropathy, or Berger's ("burrjays") Disease. This is the most common non-diabetic kidney disease and affects as many as two to four percent of the world's population.