Slashdot Mirror
New Microscope Reveals Ultrastructure of Cells
An anonymous reader writes "For the first time, there is no need to chemically fix, stain or cut cells in order to study them. Instead, whole living cells are fast-frozen and studied in their natural environment. The new method delivers an immediate 3-D image, thereby closing a gap between conventional microscopic techniques. The new microscope delivers a high-resolution 3-D image of the entire cell in one step. This is an advantage over electron microscopy, in which a 3-D image is assembled out of many thin sections. This can take up to weeks for just one cell. Also, the cell need not be labeled with dyes, unlike in fluorescence microscopy, where only the labeled structures become visible. The new X-ray microscope instead exploits the natural contrast between organic material and water to form an image of all cell structures. Dr. Gerd Schneider and his microscopy team at the Institute for Soft Matter and Functional Materials have published their development in Nature Methods (abstract)."
(checks article)
yep.
Pics or it didn't happen. I mean, seriously, an article about a new imaging technique without even a low resolution sample?
Yes I actually read TFA.
Its kinda lame to have an article on 3D images without any image samples. Thanks Medical Daily!
Okay, I read the press release copied and pasted onto a random blog. Is there a real article with pictures we could look at?
Visit the
Figures:
http://www.nature.com/nmeth/journal/vaop/ncurrent/fig_tab/nmeth.1533_ft.html
Stories like this suck.
WWJD -- What Would Jimi Do?
(Smash amp, burn guitar, take home the groupies)
Didn't find any relevant pics but if anyone's interested the research group's webpage is http://www.helmholtz-berlin.de/forschung/grossgeraete/mikroskopie/index_en.html.
As a news photographer, who naturally believes that pictures are very important in news coverage, it blows my mind that a story about a new imaging technique would run without one single illustration.
http://www.helmholtz-berlin.de/pubbin/news_seite?nid=13186;sprache=en;typoid=3228
... whole living cells are fast-frozen and studied in their natural environment.
Um, unless we're talking about species native to Antarctica, I wouldn't think that frozen would be their "natural environment".
Freezing is known (and not just by the State of California ;-) to do damage to many cell structures. For example, they no longer qualify as "living".
Somehow, I think this could have been better expressed with different words.
Those who do study history are doomed to stand helplessly by while everyone else repeats it.
The "show me" state.
Terrible misleading article. Maybe its the first time the journalist heard about it, but its hardly the first time this has ever been done.
Despite a desperate attempt by the journalist filter to avoid "science-y words" I've figured out the technique they're talking about is xray microtomography. Basically yet another tomography tech (make a 3 d model in a computer out of a crapload of 2 d pix and lots of processing and memory) but applied to little things.
"The first X-ray microtomography system was conceived and built by Jim Elliott in the early 1980s" Back then 50 nm was considered pretty good resolution, and thirty years later these dudes are down to 30 nm. A slight improvement on the past, and it is cool, but its not like they are "the first", like being the first men to step onto the moons surface or something.
http://en.wikipedia.org/wiki/X-ray_microtomography
Saying these guys are the first, is kind of like saying I'm the first human being to see the moons of jupiter thru a telescope, with the footnote that I'm defining telescope today as being home made using these exact lenses from Edmund Optics and these specific (empty) toilet paper tubes with these somewhat unique specific optical parameters, and no one has ever used that exact tech. Or I'm the first to have ever driven my car to work, while burning these specific individual hydrocarbon molecules.
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
Suppressed technology or conspiracy theory? You decide.
Wikileaks Is Democracy
What about the cells that opt out of this intrusive screening?
Revive the Constitution.
The article is freely available here or using wget:
wget --referer="http://www.nature.com/regions/germany/" http://www.nature.com/nmeth/journal/vaop/ncurrent/pdf/nmeth.1533.pdf
Its only a matter of time before the TSA starts using this at airports...
Traditional fluorescent microscopy isn't going away anytime soon. While immunohistochemistry is fairly "low resolution" optically, it does give you the ability to image individual protein targets (even if they do show up as big green and red blobs). This x-ray scope has no where close to that kind of "resolution." For the most part we already know what the insides of cells "look like." What is interesting is what the individual molecules are up to.
Here's the relevant passage from the article with the juicy bits:
We acquired X-ray microscope images of these vitrified mammalian cells at tilt angles from 60 to +60 in increments of 1 at a pixel size of either 9.8 nm (25-nm zone plate objective) or 15.6 nm (40-nm zone plate objective). Exposure times for each tilt angle were 224 s. The total X-ray exposure (~109 Gy) produced negligible radiation damage, as we detected no difference in image quality between images acquired at the beginning and end of the tilt series (Supplementary Fig. 3). We processed the images using a reciprocal space algorithm11 to generate a 3D tomogram composed of cubic voxels whose side lengths were either 9.8 nm (25-nm zone plate objective) or 15.6 nm (40-nm zone plate objective).
So they took 121 x-ray images of the specimen, with each image taking 2-24 seconds, and then stitched them together using a tomography technique to obtain their 3D volume. It's certainly faster than a few weeks, but this is not what I would consider "immediate". The article also points out that poor cryopreservation led to some artifacts and that the resolution in this technique was still not as good as the TEM; not having an entire 180 degree rotation of the object led to artifacts as well:
We did not detect some structures by X-ray tomography that we detected by TEM, such as ribosomes and the double membrane of the mitochondrial cristae. These probably fall below the current resolution limit (see below). An additional limitation was the restricted tilt angle range (±60) used in these experiments. This led to poorer resolution in the z dimension, as indicated by a distortion in the 3D shape of some organelles, which appeared more cylindrical in x-z views (Fig. 3b) as well as an inability to obtain face-on views of the nuclear pores (data not shown) or follow the complete circumference of the nuclear membrane (Supplementary Fig. 5b).
On a side note, they'll be tasty and fresh in a jiff too!
Medical Daily is a linkfarm, and Slashdot is linkspamming the world. It was shocking to see a link to the Nature abstract, though - normally I would have to Google that up for myself.
Verdict? Slashdot still sucks, but samzenpus is at least a notch above Timothy.
If you don't the difference between a lysosome and the endoplasmic reticulum, this is a great way to learn that I encountered the other day. :)
CellCraft
The Nature Methods paper in question is pretty lame. Its difficult to see why it merited publication, since there is nothing new in the paper. Other groups have been doing this kind of imaging routinely for years (and doing so without the artifacts caused by only being able to collect a relatively restricted tilt series).
Probably they needed some hype prior to submitting a funding proposal.