Editing Stanley Miller (section)

==Reassessment==

In 1972 Miller and his collaborators repeated the 1953 experiment, but with newly developed automatic chemical analysers, such as [[ion-exchange chromatography]] and [[gas chromatography]]-[[mass spectrometry]]. They synthesized 33 amino acids, including 10 that are known to occur naturally in organisms. These included all of the primary alpha-amino acids found in the [[Murchison meteorite]], which fell on Australia in 1969.<ref>{{cite journal |vauthors=Ring D, Wolman Y, Friedmann N, Miller SL |title= Prebiotic synthesis of hydrophobic and protein amino acids |journal =Proceedings of the National Academy of Sciences|volume= 69 |issue= 3 | pages= 765–768 |year= 1972 |pmid=4501592|pmc= 426553 |doi=10.1073/pnas.69.3.765|bibcode= 1972PNAS...69..765R |doi-access= free }}</ref> A subsequent electric discharge experiment actually produced more variety of amino acids than that in the meteorite.<ref>{{cite journal |vauthors=Wolman Y, Haverland WJ, Miller SL |title= Nonprotein amino acids from spark discharges and their comparison with the murchison meteorite amino acids |journal= Proceedings of the National Academy of Sciences|volume= 69 |issue= 4 | pages= 809–811 |year= 1972 |pmid= 16591973|pmc= 426569 |doi=10.1073/pnas.69.4.809|bibcode= 1972PNAS...69..809W |doi-access= free }}</ref>

Just before Miller's death, several boxes containing vials of dried residues were found among his laboratory materials in the university. A note indicated that some were from his original 1952-1954 experiments, produced by using three different apparatuses, and one from 1958, which included [[hydrogen sulphide]] (H<sub>2</sub>S) in the gaseous mixture for the first time, a result which was never published. In 2008 his students re-analysed the 1952 samples using more sensitive techniques, such as [[high-performance liquid chromatography]] and liquid chromatography–time of flight
mass spectrometry. Their result showed the synthesis of 22 amino acids and 5 amines, revealing that the original Miller experiment produced many more compounds than actually reported in 1953.<ref>{{cite journal|vauthors=Johnson AP, Cleaves HJ, Dworkin JP, Glavin DP, Lazcano A, Bada JL |title= The Miller volcanic spark discharge experiment|journal= Science|volume= 322|issue=5900|pages=404|doi= 10.1126/science.1161527|year=2008|pmid=18927386|bibcode= 2008Sci...322..404J|s2cid= 10134423}}</ref> The unreported 1958 samples were analysed in 2011, from which 23 amino acids and 4 amines, including 7 sulfurous compounds, were detected.<ref name=badajl/><ref>{{cite journal|author=Parker ET, Cleaves HJ, Dworkin JP, Glavin DP, Callahan M, Aubrey A, Lazcano A, Bada, JL|title=Primordial synthesis of amines and amino acids in a 1958 Miller H<sub>2</sub>S-rich spark discharge experiment|journal= Proceedings of the National Academy of Sciences|volume=108|issue=12|doi=10.1073/pnas.1019191108|year=2011|pmid=21422282|pmc=3078417|pages=5526–5531|bibcode=2011PNAS..108.5526P|doi-access=free}}</ref><ref>{{cite news|last=Keim|first=Brandon|title=Forgotten Experiment May Explain Origins of Life|url=https://www.wired.com/wiredscience/2008/10/forgotten-exper/|access-date=March 22, 2011|newspaper=[[Wired Magazine]]|date=October 16, 2008}}</ref><ref>{{cite news|last=Steigerwald|first=Bill|title=Volcanoes May Have Provided Sparks and Chemistry for First Life|url=http://www.nasa.gov/centers/goddard/news/topstory/2008/volcanic_life_origin.html|access-date=March 22, 2011|newspaper=NASA Goddard Space Flight Center|date=October 16, 2008}}</ref>