In 1968 Robert W. Holley, was awarded the Nobel Prize for the first sequencing of a nucleic acid—a tRNA with just 80 bases. It took Holley and his team 5 years to discover the sequence. A few years later the first genome was sequenced, that of a 5,386-bp bacteriophage. As methods gradually improved, the genome of a prokaryote was sequenced in the 1990s. With the new automated sequencing techniques we just described, we now have genome sequences for many prokaryotes, to the great benefit of microbiology and medicine.