In two common infections of the vagina, bacterial vaginosis (and sometimes in trichomonas vaginalis) your doctor may do a “whiff” test, where he or she takes some discharge, drops some potassium hydroxide on it (a base, KOH) and smells it for a fishy, foul odor. The base causes some foul-smelling amines to be released: cadaverine and putrescine. What great names.
Interestingly, some women will complain of foul odor after intercourse, and the reaction is the same: semen is basic, and when it mixes with the discharge, you get the same release of cadaverine and putrescine. Cool.