History is crucial to understanding disease. The genetic text of bacteria and viruses are constantly evolving. Culture collections offer samples of that text that has been frozen in time. In the same lab, behind a locked door, there is a locked safe. And in the locked safe there is a box. And in another box there is a tiny, tiny match box. It looks like somebodyhas sort of put gravy on a glass slide. But the label that's written on it, in very careful handwriting, says that this is alexander fleming's other well known request tof the world its penesilium.