Pictures of CATs

December 1, 2012 2:09 PM

Scientists snap a picture of DNA’s double helix for the very first time
posted by cthuljew (33 comments total)

Oh. I thought it would be like in our school textbooks, a complex double entwined array of different colored nodules, linking together.

Instead, it turns out we're made of something rather less romantically-looking. Oh well.
posted by Wordshore at 2:33 PM on December 1, 2012 [2 favorites]

If anyone wants a copy of the actual paper memail me with an email address I can send it to and a promise not to distribute it - for the purposes of the academic discussion we are about to have here of course.
posted by Blasdelb at 2:36 PM on December 1, 2012 [1 favorite]

Interesting shot. Is it okay to replicate and distribute copies?
posted by hal9k at 2:38 PM on December 1, 2012 [2 favorites]

Add the word Andromeda to the subject line and hit "Reply All"
posted by hal9k at 2:41 PM on December 1, 2012

Instead, it turns out we're made of something rather less romantically-looking. Oh well.

THERE IS BUT ONE SPRING GOD AND COILY IS HIS PROPHET
posted by The Whelk at 2:41 PM on December 1, 2012 [8 favorites]

The DNA they imaged was in the A conformation, likely due to the fact that it was in a dehydrated environment. In cells, uncoiled DNA interacts strongly with surrounding water molecules, resulting in the more familiar looking B conformation.
posted by dephlogisticated at 2:43 PM on December 1, 2012 [10 favorites]

Absence of colored notched shapes with letters aside, the coils seem tighter than all the textbook versions.
posted by Egg Shen at 2:44 PM on December 1, 2012

On preview : So they plump when you cook 'em?
posted by Egg Shen at 2:46 PM on December 1, 2012 [2 favorites]

Steady on.
posted by edd at 2:49 PM on December 1, 2012 [21 favorites]

edd's link has it. The image shows what the authors infer to be a bundle of seven DNA helices. In that case, the periodicity is likely accurate but the thickness is not.
posted by dephlogisticated at 3:08 PM on December 1, 2012

Instead, it turns out we're made of something rather less romantically-looking. Oh well.
posted by Wordshore at 5:33 PM on December 1 [+] [!]


Use your imagination.
posted by Brandon Blatcher at 3:08 PM on December 1, 2012

On preview : So they plump when you cook 'em?

We're all the same on the inside: Ballpark Franks.
posted by tommasz at 3:09 PM on December 1, 2012

In fact, only the letters F, Q, U, V, and Y are now available to describe any new DNA structure that may appear in the future.

I don't know why, but I find that sentence totally adorable. Like, "Hey, if you're writing DNA-configuration fan fic, here are some cool names you can use!"
posted by nebulawindphone at 3:10 PM on December 1, 2012 [3 favorites]

The technical achievement of what they did is pretty fucking amazing. There are two kinds of electron microscopy displayed here, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The fancy 3D pictures showing the phage λ DNA strung out across the two pillars over the hole are SEM pictures establishing the context for the shot - effectively dismissing the idea that the string shown in the close up TEM shot is anything other than the DNA the researchers say it is. To do this the researchers designed their silicon platform to have assemblies of two pillars just like that, which were exactly the correct distance apart, and had a hole in between them that penetrated the platform. They also designed it to rapidly evaporate water such that when they put a dilute solution of phage λ DNA on the platform the DNA would end up strung across the pillars over the hole. This is really cool, what it allowed the researchers to do is take a picture of the DNA without a background getting in the way and mucking up the contrast.

What it isn't is the first picture taken of DNA with an electron microscope, seriously, we've been doing that for a long time. It is also not a picture of a single strand, but six strands wound around a core seventh strand, those grooves in the string across the picture are not the major and minor groves of the double helix. Indeed, the double helix is not apparent at all from this picture.

This is some more bullshit:

"Aside from creating a cool image, the technique will allow the researchers to investigate DNA in greater detail, as well as seeing how it interacts with proteins and RNA."

The i09 writer seems to be getting it from this coy and not quite responsible statement from the authors:

"New direct methods are now necessary to understand the complex relationships between DNA, proteins, micro RNAs and transcription factors."

Which is, hey, whatever, but as someone in need of techniques like this, the authors method will be very unlikely to every be remotely useful to us. Not only does it require bundles of DNA but the evaporation procedure would fuck up DNA binding.
posted by Blasdelb at 3:13 PM on December 1, 2012 [12 favorites]

edd: "Steady on."

"What all this tells you is that Nature is a bitch who likes to make life hard for scientists. "

Nah...

Nature's not a bitch,
nature's a beautiful woman,
you only call her a bitch,
cuz she won't let you get that pussy.
posted by symbioid at 3:15 PM on December 1, 2012 [3 favorites]

Mind the gap.
posted by boo_radley at 3:20 PM on December 1, 2012

Is it okay to replicate and distribute copies?

Yes, but if you're going to do that DIY at home it takes about nine months.
posted by justsomebodythatyouusedtoknow at 3:40 PM on December 1, 2012 [2 favorites]

This FPP should be tagged with "BAD SCIENCE REPORTING".

Look at edd's link.
posted by lalochezia at 4:48 PM on December 1, 2012 [2 favorites]

Nice post title, btw.
posted by Egg Shen at 4:49 PM on December 1, 2012

The work and skill involved in this project reminds of Steven Milhauser's story In the Reign of Harad IV.
posted by Pantalaimon at 4:53 PM on December 1, 2012

This FPP should be tagged with "BAD SCIENCE REPORTING".

It probably should, though I hope the post doesn't get deleted. The two pictures with the additional context given by edd's link and the thread are indeed REALLY FUCKING COOL, even if despite the text above the fold

"Scientists snap a picture of DNA’s double helix for the very first time"

Those Scientists have names

No pictures were snapped (I know of one old school guy taking and developing real film pictures of TEM images but these guys arn't him)

The double helix of DNA was not imaged

It was not the first time DNA was imaged

It was not the first time DNA was imaged using a Scanning Electron Microscope

It was not the first time DNA was imaged using a Transmission Electron Microscope

and

Precious little of the linked article was not fundamentally wrong or the result of a serious misunderstanding of the research

posted by Blasdelb at 5:07 PM on December 1, 2012 [4 favorites]

From Slashdot's discussion on this: how DNA replicates. (Second half of video.)
posted by gjc at 5:09 PM on December 1, 2012

"Nice post title, btw."

Needs more deoxyguanosine?
posted by Blasdelb at 5:09 PM on December 1, 2012 [1 favorite]

"From Slashdot's discussion on this: how DNA replicates . (Second half of video.)"

Hey thats Drew Barry's work, if this kind of thing interestes you check out this post where the man himself showed up, and its follow up.
posted by Blasdelb at 5:13 PM on December 1, 2012 [1 favorite]

Precious little of the linked article was not fundamentally wrong or the result of a serious misunderstanding of the research

Seriously. Even the title makes me twitch. X-Ray crystallography is pretty close to "seeing" things like your eye does, given that it uses photons (albeit in a reciprocal space). Last I checked I don't shoot beams of electrons out of my eyes.
posted by Orange Pamplemousse at 5:56 PM on December 1, 2012 [1 favorite]

"It has not escaped our notice that the specific structure we have observed immediately suggests a possible mechanism for the drying of tiny molecular clothes. "

(Stolen from the comments to the linked io9 article)
posted by metaBugs at 6:19 PM on December 1, 2012

I think I can see some midichlorians in that picture!
posted by XMLicious at 7:19 PM on December 1, 2012

Precious little of the linked article was not fundamentally wrong or the result of a serious misunderstanding of the research

Seriously: This was a shoddy attempt at science journalism.
posted by Blazecock Pileon at 7:24 PM on December 1, 2012

What all this tells you is that Nature is a bitch who likes to make life hard for scientists

I am a woman and a feminist and an earth ecstatic and also a PhD scientist, and this sentence makes me want to slap the living shit out of it author. Maybe if I were sufficiently evolved I would be drawn to some sort of life-affirming alternative, but I ain't there yet and goddamn if my arm isn't twitching at the very thought.
posted by Sublimity at 11:33 AM on December 2, 2012 [4 favorites]

"Nice post title, btw."

Needs more deoxyguanosine?

G-CATs (like G-men--little FBI felines).
posted by MikeKD at 3:59 PM on December 2, 2012

We're counting on io9 for our science news now? That's a step worse than the usual New Scientist single link FPPs.
posted by aught at 7:24 AM on December 3, 2012

Instead, it turns out we're made of something rather less romantically-looking. Oh well.

As long as I'm in cranky nitpicking mode: we're not "made" of DNA any more than a house is made of blueprint paper, building materials specs and regulations, and construction tools.
posted by aught at 7:27 AM on December 3, 2012

Well, if the average human is 65 kg, or 24.8 kg by dry mass, and they have 0.7 kg of total human DNA then that would make them 2.8% DNA by dry mass, or at least significantly made of DNA.
posted by Blasdelb at 8:11 AM on December 3, 2012