View Single Post
Ryan_m_b
#41
Feb5-12, 12:22 PM
Mentor
Ryan_m_b's Avatar
P: 5,405
Quote Quote by Murdstone View Post
Arsenic used as a replacement for phosphorus...

Article does open up the possibility of life much different than on Earth, elsewhere. Not to suggest that because of this life does exist off planet, but if it does it can be more unusual than anticipated.
Did you not read the post directly above yours? Here it is again (key points bolded):
Quote Quote by Ygggdrasil View Post
Update: Rosie Redfield, a professor of zoology at the University of British Columbia and outspoken critic of the arsenic life paper, claims she has performed experiments to refute the main conclusion of Wolfe-Simon et al.'s paper. She has posted a non-peer-reviewed preprint of her manuscript on Arxiv.

In the manuscript, Redfield and co-workers detail experiments attempting to replicate growth of samples of the GFAJ-1 bacterium and, contrary to what was reported in the original paper, do not find that the bacterium displays arsenic-dependent growth. The authors also set out to test one of the boldest claims of the Wolfe-Simon paper: that the bacterium incorporates arsenic into its DNA. The authors employ a more rigorous DNA purification procedure than Wolfe-Simon et al. (they add a CsCl density centrifugation step), then digest the DNA for LC-MS analysis to look for evidence of arsenic. They find no evidence of arsenic incorporation into the DNA. Furthermore, their results suggest that the purification methods used in the Wolfe-Simon paper leave traces of free arsenic associated with the DNA, but this free arsenic is removed with more extensive washing and purification. This result suggest that the apparent incorporation of arsenic into DNA seen by Wolfe-Simon et al. was merely free arsenic that was incompletely purified from the DNA.

For more, you can read the following news articles from Science and Chemical and Engineering News or follow the story on Redfield's blog:
http://news.sciencemag.org/sciencein...-fails-to.html
http://cen.acs.org/articles/90/web/2...Aftermath.html
http://rrresearch.fieldofscience.com...%23arseniclife