Every Thursday, Laboratory Equipment features a Scientist of the Week, chosen from the science industry’s latest headlines. This week’s scientist is Jeffrey Bada of the Scripps Institution of Oceanography at UC San Diego. He and a team analyzed samples of prebiotic materials created in 1958 by the famous chemist Stanley Miller.
Q: What made you interested in analyzing Stanley Miller's samples from the 1950s?
A: Analytical techniques have advanced so far beyond what Miller had available in the 1950s, we thought it would be important to show the total distribution of amino acids that had actually been synthesized. Also, samples from experiments in 1958, like the cyanamide samples we just reported, were never analyzed by Miller for unknown reasons.
Q: What are the future implications of your research and findings?
A: The findings of our studies of the old Miller samples indicates there is still a lot to learn from his classic spark discharge experiments. For example we know that another class of compounds, alpha-hydroxy acids, are also synthesized in the spark discharge, but none of Miller's early experiments investigated these compounds in detail. Unfortunately when Miller partially purified his early spark discharge samples, the hydroxy acids were not saved. So we are now repeating the experiments to determine the distribution of this other important set of compounds.
Q: What was the most surprising thing you found in your research?
A: I think what is most surprising is that Miller did not analyze some of his probably most important samples, for example the ones done in 1958.
Also, the use of cyanamide was way ahead of it time in that no one suggested this as a possible prebiotic compound for peptide synthesis until at least a decade later. How Miller got the idea to use this is unknown.
Q: What is the take home message of your research and results?
A: Probably the most important aspect of our research was the availability of Miller's laboratory notebooks that describe his various experiments.
Without these we would not been able reconstruct how the experiments were carried out. The take home message is: take good notes and save these, and do not throw away any samples or material from important experiments.
Q: What new technologies did you use in your lab during your research?
A: We used state-of-the-art high performance liquid chromatography coupled with various state-of-the-art mass spectrometry methods for this research. In fact one of the mass spectrometry methods was developed during the course these studies — this was not just developed for our work, but as a general analytical tool.
Q: What is next for you and your research?
A: As I mentioned, we are now in the process of redoing several of Miller's experiments. We are particularly interested in whether cyanamide can act as a co-polymerization reagent for amino acids and hydroxy acids. These polymers, called polydepsipeptides or poly(ester amide)s, have very interesting properties, some of which are possibly of importance in the chemistry that gave rise to the first self-replicating entities.