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A while ago a NASA funded study claimed that they could get bacteria to incorporate arsenic into their DNA.

Life forms based on different elements than life on earth have been speculated about in science fiction for a long time, the most prominent, hypothetical example is probably silicon-based instead of carbon-based life. Now, arsenic and phosphorus are in the same group in the periodic table like carbon and silicon are. This is the first study I know of that claims that life based on different elements is really possible.

Did they conclusively show that life forms based on arsenic-containing DNA are possible, or is this an overhyped and exagerrated conclusion?

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Here's an article from a scientist pointing out the flaws in the research.

Basically, the measurements are questionable, due to sloppy controls.

In a more general sense, in order to conclusively show something, someone not supporting NASA would have to replicate the experiment. So far that has not happened, and most of the press is on how badly they screwed up protocols.

Other articles:

Right now, it appears to be in the one-experiment-and-a-lot-of-opinions stage, which is very far from conclusive.

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You may enjoy the article NASA did not find arsenic-based life.
Those bacteria can use arsenic instead of phosphorus if forced to, but do not use it naturally. Yet this achievement is still cool.

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    Even the “instead of” part is questionable. For example, the research failed to show conclusively that the bacteria actually incorporated arsenic into their DNA, and given what we know about the structure of DNA this is highly unlikely. – Konrad Rudolph Mar 17 '11 at 18:14
  • This fails to address the question of whether or not arsenic-based life is possible. – Avi Mar 11 '13 at 17:23
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    @KonradRudolph "Quantitative Study of As (V) and As (III) Interaction with Mangrove DNA by Molecular Fluorescence Spectroscopy" Bull Environ Contam Toxicol (2014) 93:177–181 studies the replacement of phosphate with arsenate and arsenite in DNA in vitro. link.springer.com/article/10.1007/s00128-014-1265-y – DavePhD Feb 19 '16 at 13:48

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