Awesomics

It is really remarkable how so many things in biology, which we take completely for granted, were adopted by accident. One example: When scientists run a gel to separate DNA molecules, they usually add ethidium bromide to the agar. Ethidium bromide is a fluorescent dye that locks into the DNA grooves and emits a red-ish color when you shine a UV light on it. It's an easy way to see where DNA ends up in the gel. But the only reason Ethidium Bromide staining even happened is because of a broken centrifuge. In 1972, two Dutch scientists (Cees Aaij and Piet Borst) were trying to separate DNA isolated from mitochondria. They were spinning down the DNA inside of a big centrifuge, and the machine broke. Undeterred, the duo decided to separate their DNA using gels instead. Agarose gel electrophoresis had been used since the 1960s to separate radiolabeled DNA. The DNA molecules were modified to carry a radioactive isotope (usually heavy phosphorus) and then scientists would move them through the gel and use a radiation detector to figure out where the DNA went. This was obviously both tedious and dangerous. The brilliant insight that Aaij and Borst had was, instead, to just add ethidium bromide to the gel so that the DNA would "light up" instead. No radiation needed. The Dutch scientists stopped using their centrifuge entirely and began separating DNA molecules using this new approach instead. Their discovery spread quickly. (The first gels looked like garbage, though!)