Old mold from penicillin discoverer auctioned for $14,617

Fleming "sent these samples out to dignitaries and to people in the scientific world, almost as a kind of holy relic," said Matthew Haley, director of books and manuscripts at the auction house Bonham's.

"When it first became available, penicillin was called a miracle drug," said Kevin Brown, archivist at the Alexander Fleming Laboratory Museum .

"Fleming noticed something that other people would have missed and saw the potential of penicillin to treat patients," said Brown.

Scientists at Oxford University further developed penicillin, and production was ramped up so that enough of the antibiotic would be available for the Allied invasion on D-Day in 1944.