can be used to make various medicines - like insulin - that people need

can be used to make various medicines - like insulin - that people need.

In former times, most insulin-dependent diabetics had to depend on insulin harvested from pigs that had been slaughtered for food. But what if you were allergic to pork, or couldn't use porcine products because of religious objections? Human insulin was sometimes available, but it was in short supply and was very expensive.

Once scientists figured out how to place genes into bacteria, someone had the idea to place the gene for human insulin into the bacterial genome. Given the right nutrients, the bacteria could be grown in culture and produce lots of human insulin. Nowadays, human insulin, along with a number of other human proteins needed for medical uses, produced by transformed bacteria are widely available.