Marshall Warren Nirenberg

Michigan's scientific alumni have received Nobel Prizes, developing life-saving treatments, and pushed the boundaries of human knowledge.

In 1968, alumnus Marshall Nirenberg shared the Nobel Prize in Medicine for cracking the genetic code, just one example of Michigan graduates' contributions to scientific achievement.

Today, the University of Michigan's influence extends far beyond the American borders.

With students from all 50 states and over 100 countries, the university is truly global in its outlook and impact.

Cracking the code was an experimental problem, and in mid-1961, no one had a plan.

In the same year in Moscow, Marshall Nirenberg, a young researcher at the National Institutes of Health, and a German postdoc, Heinrich Matthaei, announced an experiment.

They took the innards of bacteria, of all its, you know, in- internal machinery, and added a synthetic messenger made of a single letter repeated over and over, UUUUU.

It's like a Morse code equivalent.

It was the first word of the genetic code anybody had ever read.

It's almost like there was suddenly a, a way in.

Matthew Meselson of Harvard realized what he was hearing and ran to tell Crick, who arranged for Nirenberg to speak again to a far bigger audience.

So the popular story is a three-way race, Nirenberg, Ochoa, and Khorana.

If you add or remove only one or two, you break the whole system.

And that brings us to the first of a hugely important set of studies that was published by the scientists Marshall Nirenberg and Heinrich Matthaei.

They broke open E. coli cells so that all the machinery inside, the DNA, RNA, ribosomes, all of it, were exposed to the environment in the test tube.

Then they provided their own cocktail of amino acids in which one amino acid, called valine, was radioactive.

This gave a lot of support to that central dogma, that DNA is used to make RNA, and RNA is used to make proteins.

Okay, but we still don't know which codon does what, which brings us to the second paper.

Here, Nirenberg and Matthaei did basically the same thing as before, but this time, instead of using RNA from E. coli or any other organism, they used RNA that they synthesized themselves in the lab.

This RNA consisted only of uracil, so it was just UUUUUUUU, et cetera.