Switchable Net Woven from DNA

virtualXTC writes "A team of US researchers have managed to make a woven DNA mesh that expands and contracts. By coating the net in silver they can make nano-wire lattice in which individual wires can be lengthened or shortened using a short snippet of ssDNA to create a nano-switch."

Re:First Post!

[Squiffy]

I guess now they can say, "Every dark nucleotide has a silver lining."

Re:First Post!

[Kethinov]

Well, at least one of them got modded funny. ;)

I believe Tycho said it best.

[devphil]

In relation to another recent weird-science happening:

If you already knew that human beings were doing this kind of thing, by which I mean the spider-goat thing, my hat's off to you. We never heard about this shit until a week ago, which is surprising because when someone squeezes some Goddamn spider silk out of a goat's titty it's the kind of thing one expects to hear about. Industry is clacking its hideous mandibles with excitement over the applications of readily available spider silk, focused largely on the swinging and thwipping sectors of our economy. I'm making goofy jokes about it because I think that we are a young species that often fucks with things we don't know how to unfuck. It's a coping mechanism.

from Penny Arcade [penny-arcade.com]

DNA again

[tsa]

At our research institute there is also a lot of research going on in the use of DNA in nanotechnology. I always get the feeling this is mainly because adding the word 'DNA' in the proposal increases the chances that your proposal gets approved and you get the money you want enormously. Of course there are a lot of buzzwords in this /. post about how this invention can lead us to a better future for all, but I wonder whether this could be done simpler with cheap standard polymers? On the other hand, DNA almost is a cheap standard chemical already.

Re: DNA again, Why it must be DNA

[G4from128k]

Although "DNA" is a buzzword designed to excite grant reveiwers, in this example it is required.

The DNA switch described in the article uses base-pair code matching to do its magic. Thus the invention requires a polymer that contains a controllable sequence of monomers. At this time, I think DNA and RNA are the only polymers that have a well developed technology for controlling the exact sequence at the molecular level and for mass producing polymers with an exact sequence.

For this work, at least, D

DNA Switch != Practical Computer

[G4from128k]

We must remember that DNA-switches are radically different from the semiconductor switches used in current computers. The biggest difference is that DNA switches are not addressable by location -- you can't easily build a trace that carries a signal to or from a particular chunk of DNA. Thus you cannot layout a complex switching circuit in the same way you build an electronic CPU.

On the other hand, DNA is code-addressable and innately parallel in solutions. Create a liquid with molecules of one code and it will automatically find its match in the solution or on a substrate. This is an intensely parallel process with trillions of molecules bumping and matching simultaneously. The degree of parallelism is only limited by the permitted reaction time, total amount of reactants, and the relative concentrations of the matching components. (Imagine a computer that increases in power just by pouring it into a bigger beaker.) The result is that DNA-based systems can be massively parallel machines, but the likely clock rates will be a few Hertz at best.

The point is that DNA-based computers have totally different design principles from their semiconductor brethern. Until we get good at compiling algorithms into a sequence of code-match chemical reactions and create the substrate and chemical systems to reliably carry-out very long chains of DNA-based computations, we won't have a practical DNA-based computer.

Re:DNA Switch != Practical Computer

[Salis]

Actually, DNA is location addressable. DNA is composed of nucleotides with a specific sequence. The sequence itself is the "address" of a site on the DNA. LOTS of proteins specifically bind ONLY to certain sites on DNA, making them "location addressable".

Look up Cre/LoxP, V(D)J recombination, transcriptional operators, and the list goes on and on..

DNA and RNA will also hybridize only to specific sequences, or undergo homologous recombination with partially homologous regions. This is what the researchers

Re:DNA Switch != Practical Computer

[G4from128k]

I think we are using different words to say the same thing. With electronics, I can direct a signal to a particular physical location in a circuit. The physical locational configuration controls everything.

Wth DNA, a given sequence will find and match its target regardless of the physical "location" of the target -- it does not care if the match is in the upper half of the beaker of liquid or 1 mm from the top right of the substrate or at base pair #237283 instead of base pair #237284. Nor is it easy

Re:DNA Switch != Practical Computer

[Salis]

But, if you code in a sequence that is 30 nucleotides long as "locations" you are almost gaurenteed that the 30 nucleotide sequence is UNIQUE to the DNA.

But, of course, DNA is just floating around and you don't know exactly where the DNA really is...only that if you want to target Gene X on Chromosome Y you need a XXXXXXXXXXXXXX sequence to probe.

I think what you're saying is that DNA "addresses" are less precise than circuit addresses. They probably are... but they are also more flexible in information s