The first ever Pap smear was not done on a woman in a doctor’s office, but a drunken guinea pig in a laboratory.

Many years ago, George Papanicolaou, the inventor of the Pap smear, set out to determine the effects of alcohol on guinea pigs and their offspring. Papanicolaou needed to study the guinea pigs’ eggs pre-ovulation. The problem was determining when the guinea pigs were menstruating and the solution, he found, was the first-ever Pap smear.

Papanicolaou, who had originally trained as a doctor in Greece, conducted his alcohol study in America in 1912. The samples Papanicolaou extracted from the drunk guinea pigs helped him track the animals’ sex cycles, and his work was of such a caliber that others soon joined in his study.

Ultimately, Papanicolaou was able to gather cell samples from women. While he was also able to track their sexual cycles by their cells, more importantly, he was able to associate certain abnormal cells with cervical cancer.

Today, Pap smears are used to reliably test and diagnose cancer and have saved tens of thousands of women’s lives. And it’s all thanks to a couple of drunken guinea pigs and the ambitious Papanicolaou.