C57BL/6

C57BL/6, often referred to as "C57 black 6", "C57" or "black 6" (standard abbreviation: B6), is a common inbred strain of laboratory mouse.

It is the most widely used "genetic background" for genetically modified mice for use as models of human disease. They are the most widely used and best-selling mouse strain, due to the availability of congenic strains, easy breeding, and robustness.

Appearance and behavior

C57BL/6 mice have a dark brown, nearly black coat. They are more sensitive to noise and odours and are more likely to bite than the more docile laboratory strains such as BALB/c. They are good breeders.

Group-housed B6 mice display barbering behavior, in which the dominant mouse in a cage selectively removes hair from its subordinate cage mates. Mice that have been barbered have large bald patches on their bodies, commonly around the head, snout, and shoulders, although barbering may appear anywhere on the body. Both hair and vibrissae may be removed.

C57BL/6 has many unusual characteristics that make it useful for some work and inappropriate for other: It is unusually sensitive to pain and to cold, and analgesic medications are less effective in it. Unlike most mouse strains, it drinks alcoholic beverages voluntarily. It is more susceptible than average to morphine addiction, atherosclerosis, and age-related hearing loss.