In the early 1980s, Kary Mullis developed the polymerase chain reaction, an elegant way to make copies of a DNA strand using the enzyme polymerase and some basic DNA "building blocks." The process opened the door to more in-depth study of DNA -- like the Human Genome Project. Mullis shared the 1993 Nobel Prize in Chemistry for developing this technique.

As he tells it, after winning the Nobel Prize, his next career move was to learn how to surf. It's typical of Mullis, whose scientific method is to get deeply curious about a topic, work it out from first principles, and then imagine the next giant leap forward. As he puts it in his Nobel autobiography, revised several times since 1993, "I read a lot, and think a lot, and I can talk about almost anything. Being a Nobel laureate is a license to be an expert in lots of things as long as you do your homework."

Most recently, he's been taking a hard look at immunity; a recent patent from his company Altermune describes the redirection of an existing immune response to a new pathogen.