Where the White Lab Mouse Came From

Among the signature icons of science, the white lab mouse is also among the most evocative: an animal design, bred, and built to be experimented upon, dosed and dissected. The white mouse looks pure, almost sterile, and captures so much of what we expect from modern science: uniformity and predictability. These days, you can buy lab mice like any tool or gadget. They even have names like CD-1 and J:NU 007850.

So where does the white lab mouse come from?

There are a few stories out there, but perhaps the earliest use of the white lab mouse occured in a small village of Wollstein, Germany (now Wolsztyn, Poland) in the 1870s.  The story is this:

At the time, Robert Koch was a struggling young physician in Wollstein, with a keen desire to make his mark in the world. When an epidemic of anthrax afflicted nearby sheep farms (Wollstein, as the name suggests, was a center of wool production), Koch decided he'd put a new microscope to use and try to discern the cause.

For weeks, Koch conducted experiments, trying to isolate the strange animals he saw swimming in the blood of diseased animals. He kept a backyard menagerie of guinea pigs and rabbits with his daughter, Gertrud, and these animals proved useful: he would isolate the particles and grow them, then inject them in another animal. As Koch's experiments went on, Gertrud grew concerned that she was losing all her pets. He needed a new pool of animals to experiment upon. So Koch and his wife set mousetraps in the horse barn behind their house. 

They caught a bounty, and stuffed them into tall glass jars with some holes pocked in the lid for air. When Koch needed an animal, he pulled one out, tail-first, using an old bullet extractor he’d saved from the war. After the mouse died, Koch would dissect it, searching for the bacteria – and then disposing of the cadaver by burning them in the oven. After several months, Koch had successfully repeated his experiments to his satisfaction. He had proven that anthrax was caused by these bacteria - the first definitive evidence that a disease was caused by a germ.

Clearly, Koch needed a better, more consistent supply of animals. By happenstance, a friend sent Gertrud some white albino mice as pets. The animals began reproducing rapidly, and soon Koch had taken the pick of the litter and nurtured them into a new supply to be used in his lab on other experiments. 

These became one of Koch’s most iconic contributions to science: the white lab mouse.

(There's lots more on Koch's contributions to science, including the invention of the Petri dish, in The Remedy)