Laura Defrancesco | Jun 10, 2001 | 6 min read
Europeans have destroyed 4.5 million cows since 1996, the height of the epidemic in the United Kingdom, because they were believed to be at risk for mad cow disease (bovine spongiform encephalopathy, or BSE).1 Necropsies, however, showed that only a few hundred thousand of them actually were infected.2 Had a diagnostic test for mad cow disease existed when this epidemic erupted, these numbers might have been different. But no such test did exist. The only available assay was a bioassay in which