Miller-Urey 'origin of life' experiments: A safer recipe for primordial soup

Stanley Miller performs his famous experiment in issue 1 of "Astrobiology: The story of our search for life in the Universe." 

Credit: NASA Astrobiology /artwork by Aaron Gronstal.

Researchers have published a simpler, safer method for conducting Miller-Urey origin of life experiments—which may still yield new insight about how life began on Earth.

Back in 1953, Stanley Miller, working at the University of Chicago with Harold Urey, showed how easily one could cook up life's building blocks by simulating the conditions on early Earth.

The famous recipe went as follow:

• Boil some water to mimic evaporation of the early ocean.
• Add a few gases thought to be present in the early atmosphere.
• Apply a jolt of electricity to simulate lightning.
• Let run for a few days—and you're left with a brownish soup of amino acids, the building blocks for everything alive on Earth.

Left: Harold Urey (1893-1981), investigator of the origin of life on Earth. Photo by Kemi, courtesy of the Nobel Foundation. 

Right: Urey's student and colleague Stanley Miller in their lab at the University of Chicago in 1953. 

In their experiments, they attempted to study the origins of life by duplicating the conditions which would have existed on the primordial Earth. 

Their apparatus contained a "sea" of purified, sterile water under an "atmosphere" of hydrogen, methane, and ammonia. Incandescent electrodes imitated lighting and ultraviolet radiation from the Sun. 

After a week or so the result was a tar-like residue containing amino acids, the basic building blocks of life. Photo courtesy of SPL/Photo Researchers Inc.

But while the success of the Miller-Urey experiment kicked off an entire field of research, Miller had one basic piece of advice for anyone who'd want to try it out: "Don't do it."

Jeffrey Bada

"Stanley was always afraid it might lead to a disaster," explains Jeffrey Bada, who was a student of Miller in the 1960s and is now Distinguished Prof of Marine Chemistry at SCRIPPS Institute of Oceanography.

"If you were not careful to let all the atmospheric air out, the setup could explode. So unless they were highly trained, he'd always advise people against repeating the experiment."

The original box containing archived spark discharge samples prepared by Stanley Miller in 1958. 

The label shows Miller’s original writing: p 114 refers to his notebook. 

Credit: Jeffrey Bada and Robert Benson /Scripps Institution of Oceanography, University of California at San Diego

But now a team including scientists from the Georgia Institute of Technology (GATech), NASA (including Prof. Bada), and the Tokyo Institute of Technology (TITech) have recreated a simpler and safer way of conducting Miller-Urey type experiments.

Along with written instructions, the new version was published this month in a step-by-step video format in the Journal of Visualized Experiment (JOVE).

More information: See issue 1 of "Astrobiology: The story of our search for life in the Universe" here: www.astrobio.net/index.php?option=com_content&id=7