Arsenic life not based on arsenic...

Few people who read popular science websites would be unaware that about this time last year a paper was published in Science that claimed a bacteria could incorporate arsenic into its DNA. The paper sparked a storm of controversy for the way the news was announced at a press conference and for the way that the science was done. The lead author, Felisa Wolfe-Simon, NASA (who funded the research) and even Science took flak for the publication of the paper (see Carl Zimmer's compendium of critical responses).

Now one of the most vociferous critics, Rosie Redfield, has published a paper with a team of other researchers that has failed to replicate the results of the initial paper. Another team has also published a paper alongside the Redfield paper. They too, failed to reach the same results as Wolfe-Simon. The conclusions of both the new papers were essentially the same; there was enough phosphorous in the medium to allow the bacteria to grow and there was not arsenic in its DNA.

But, it is apparently not the end of the saga. Felisa Wolfe-Simon has stated that the two new papers "are consistent with our original paper". The new results are completely at odds with the claims made in the initial paper, so it'll be interesting to see how she demonstrates that there are no discrepancies. She has promised that she and her collaborators will have a new paper out in the next few months.