Sublime

An effective antibiotic needs to disrupt a vital bacterial process without affecting related human processes.

Remarkably, about half of all useful antibiotics target bacterial ribosomes.

Spring Harbor Laboratory on Long Island, created viruses with radioactive tracers in their DNA. They allowed the viruses to infect E. coli and then pulled off their empty husks in a fast-spinning centrifuge.

make neither the amino acid methionine nor biotin, a B vitamin. The other strain he picked couldn’t make the amino acids threonine and proline. Lederberg put the bacteria in a broth he stocked with all four compounds so that the mutant microbes could grow and multiply. They mingled in the broth for a few weeks, with plenty of opportunity for hypoth

Tatum pelted colonies of E. coli with enough X-rays to kill 9,999 of every 10,000 bacteria. Among the few survivors he discovered mutants that could grow only if he supplied them with a particular amino acid. Helped along, the mutants could even reproduce, and their offspring were just as crippled. Tatum had gotten the same results as he had with b

the bacteria had the immunity embedded in their DNA so it was passed from one generation to the next.