In the first comprehensive study of the DNA on dollar bills, researchers at New York University's Dirty Money Project found that currency is a medium of exchange for hundreds of different kinds of bacteria as bank notes pass from hand to hand.
By analyzing genetic material on $1 bills, the NYU researchers identified 3,000 types of bacteria in all—many times more than in previous studies that examined samples under a microscope. Even so, they could identify only about 20% of the non-human DNA they found because so many microorganisms haven't yet been cataloged in genetic data banks.
In the first genome study of the DNA on money, NYU researchers identified 3,000 types of bacteria on a set of one-dollar bills collected in New York.
- Total DNA found: 1.2 billion segments
- Percentage human: 27%-48%
- Bacterial DNA: 54 million segments Sampler of bacteria identified:
- Acinetobacter species:antibiotic-resistant infections
- Staphylococcus aureus: skin infections
- Bacillus cereus: food-borne illness
- Escherichia coli: food poisoning
- Helicobacter pylori: gastric ulcers
- Corynebacterium diphtheriae: diphtheria
- Material: Cotton-linen blend.
- Lifetime: 21 months
- Weight: 1 gram. Since there are 454 grams in one pound, there are 454 dollar notes in one pound.
- Bulk: 1 million dollar bills stacked in a square would measure about four feet tall, four feet wide and four feet thick.
- Wear and tear: About 4,000 double folds (forward and backward) are required before a dollar note will tear.
- Annual replacement: About 45 % of the notes printed each year are $1; 95% are used as replacement notes.