Non-carbon DNA?

Every once in a while you hear somebody say that DNA could also be formed from other elements, like silicon.

Well, we've gotten to the point where we can create our own little DNA fragments, but has anyone heard of anyone cooking up some chunks of DNA from something other than carbon? That would be cool.

Just wondering.

I do not know as of yet wether it has been tried or not.
I did a google search, and came up with nothing but papers on the possibility of the subject.

If we do build DNA using non carbon-based materials, we will probably still stick to the original carbon based method, as we have alot more understanding of it at the moment.
Should we find a need to bio-engineer a new life form, it would likely be done using carbon DNA. You would save on having to do excessive research, plus, we don't know how a non Carbon DNA strand would react to day to day radiation, chemical instabilities, etc. It could end up breaking down and degrading alot faster than it's carbon counterpart.

Cooking up some silicon DNA would be proof of concept, and would be HUGE. As of right now the idea of non-carbon based life is theoretical. If we were able to prove it to be possible, we would be able to accurately expand our search criteria for life elsewhere.

I don't think it's so much non-carbon DNA they're talking about as it is just forming analogs to organic molecules at all.

Whatever you use has to form long strings of itself in order to build up complex enough organic analogs. And silicon is about the only thing that will do it. But silicon doesn't make long enough strings compared to carbon, and it's fragile when it makes the complex structures it can make.

At a temperature low enough to be stable, it forms very slowly. So a silicon based lifeform would most likely never evolve in the lifetime of the universe. Your best bet is that any lifeform you see will most likely be carbon based, but it may not be DNA based. I would imagine that there are other structures that would work just as well for information storage.

On the other hand, maybe there are lifeforms you could make with silicon that aren't at all like carbon compounds, and the guys that are nay-saying aren't paying attention to, say, crystalline lifeforms or something.

It wouldn't be possible. Silicon as an element is more than double the size of carbon (14 vs 6, not counting neutrons), and it would destroy the DNA conformation. Even normal molecules, ie those we usually talk about from cells, wouldnt be possible.