Nano-Probes Stay Inside a Cell's Nucleus for Days

Roland Piquepaille writes "Researchers from the Lawrence Berkeley National Laboratory (LBL) have developed fluorescent and stable nano-probes which can stay inside a cell's nucleus for hours or even days. According to this LBL news release, this will help biologists to better understand nuclear processes that evolve slowly, such as DNA replication, genomic alterations, and cell cycle control. This research was partially based on previous investigations about quantum dots. Now, the researchers want to tailor their quantum dots, which emit different colors depending on their sizes, to check specific chemical reactions inside nuclei, such as how proteins help repair DNA after irradiation. Read more for other details and references and to see how a nano-sized probe is entering a cell's nucleus."

Comments

Resistance is futile

[Anonymous Coward]

One step closer to Borg technology. Awesome.

Pah!

[Anonymous Coward]

That's not news. My girlfriend been telling me I've a nano-sized probe for years, now.

Uh...

[sp3tt]

"such as DNA replication"
Genetic pr0n? Sure tells us a lot about the minds of scientists.

Alarmist

[ossington]

Am I the only one who's scared that they've managed to create nanobots that can stay inside of us?

Re:Alarmist

[dan dan the dna man]

I think you misread "bots" for "dots"... if indeed you even RTFA ;)

Re:Alarmist

[Evil W1zard]

These really aren't nanobots. The definition of nanotechnology comprises any technological developments on the nanometer scale, usually 0.1 to 100 nm. In my opinion I believe that when you say the word "nanotechnology" most people today would think of super tiny robots (thanks to tv and movies). With that said these are not tiny little robots, they are crystals. So there is no reason to be alarmed because the the nano-sized attack robots have not yet been made.

Re:Alarmist

[Eosha]

Does that mean we can't use any "welcome our microscopic fluorescent overlords" jokes?

One word..

[The Jon]

..medichlorians.

Re:Dear god, not another one.

[CdBee]

That's probably not helpful. Posting it as an AC, even less so.

Question to the mature Slashdot community. I'm aware that Piquepaille runs a site called Technology Trends which at a brief examination seems to be a reasonably typical tech site written from an insider's PoV, so he's well qualified to submit at Slashdot.. but how does he do it so often?

This isn't just sour grapes - I had a story accepted once and I rarely submit - but this guy's so prolific it makes me wonder what he's doing right.

"Nanoprobe"

[jokestress]

That's my nickname for my ex-boyfriend! /here all week //try the veal

Observe without interfering?

[amanox]

I'm just curious : how can they observer without interfering the process they observe? I'm no biologist, but I'm pretty sure the nucleus must have some kind of reaction to a foreign body entering it. Not to mention the recation coused by the illuminating the nucleus: these probes seem to emit some kind of light. This must have at least some effect on the readings they get from these probes.

Re:Observe without interfering?

[janek78]

It's been a long time since my biology classes, but I can't think of any reaction to foreign body inside a cell (at least not in the usual way). A cell hasn't got an immune system of it's own. Of course it has systems capable of expelling foreign/toxic chemicals out of the cell (exocytosis, pinocytosis), but it is altogether different from say your body's reaction to a foreign body. So these microcrystals will probably in some way interfere with the inner working of the cell (it trying to expell it) but they do not neccessarily need to interfere with the actual working of the nucleus.

Re:Observe without interfering?

[Lavaeolus]

You can actually stick all kinds of stuff into a cell without causing problems (unless you react with the contents chemically, or disrupt the cell membrane). You can even add functionality to the cell, for example by injecting additional DNA, and it will treat the new material as part of itself. This is how viruses work, and the only defense is to eradicate the virus before it infects the cell, or destroy the infected cell completely.

As to the light produced, I doubt this will have a negative effect unless heat is produced too.

Re:Observe without interfering?

[mforbes]

The word 'quantum' in 'quantum dot' is misleading. The dimensions of a quantum dot are typically between a few nanometeres (billionths of a meter) to a few microns. Smaller ones, down to a single electron, can be made, and at that size they would definitely be subject to the laws of quantum of physics-- but at the more typical sizes, they're too big to worry about wave functions, and behave more like the everyday materials with which we're familiar-- except for those properties such as hue and reflectivity that are tailored during fabrication.

For more information, check out this site.

Re:Observe without interfering?

[allnameswheretaken]

A cell does have a defense system of its own. How else would some bacteria have resistance to virii?

One of the ways that molecular biologists knock out genes that they wish to study is by a proccess called RNA inteference. They do this by inserting a peice of DNA with the complementary sequence of the targeted gene. The cell then transcribes both the gene and the opposite gene into mRNA, these two mRNA fragments hybridize forming double stranded RNA. A typical cell never has stranded RNA (virii do cause double stranded RNA though). The cell recognises the double stranded RNA and digests it an enzyme. The beuty of this method is that it can be regulated, instead of knocking the gene out they can reduce the levels of transcription or only knock the gene out once the organism has reached maturity

Prokaryotes have a much simpler method for dealing with foreign DNA. The deal with it by break down any DNA with certain sequences (say ATGA) which would cut on average every 2^4 base pairs

Re:Observe without interfering?

[Anonymous Coward]

fluorescent dyes are used in all kinds of molecular biology experiments; generally they don't interfere with biological processes although in some cases they do (some of the larger dyes do cause spatial hinderences). quantum dots are sooo much smaller than current dyes that they're virtually guaranteed to not interfere. and the light they emit is extremely limited; the cool thing with quantum dots (and their detectors) is that you can detect single or at least handful of photons.. that's not going to illuminate the nucleus. completely different size scales; it's like throwing a ping pong ball at the sun, not gonna affect it.

Re:Observe without interfering?

[LiENUS]

Just a note. Pinoctytosis is for bringing forein materials in and exocytosis is for sending proteins out of the cell via the golgi aperatus, neither are really for spitting out foreign/toxic chemicals.

fluorescent

[hovercraftSpareWheel]

...fluorescent and stable nano-probes which can stay inside a cell's nucleus for hours or even days.

Now we can mod our heads to match our PC cases!

Yet another Ronald Piquepaille article

[nyri]

I will give him a little credit as he links sometimes to intresting articles. But I must say that his blog sucks big time. He has scored a slashdot.org article 13 times this year. From Ronalds account page:
Robotic Nanotech Swarms on Mars... in 2034 14:54 Wednesday 30 March 2005
Nano-Probes Stay Inside a Cell's Nucleus for Days 19:42 Tuesday 29 March 2005
The Rise of Smart Buildings 22:19 Saturday 19 March 2005
3D Virtualization Edges Toward the Mainstream 21:57 Sunday 13 March 2005
Taking Care of Mobile Patients 20:20 Saturday 26 February 2005
Smart Holograms Used as Biosensors 20:22 Sunday 20 February 2005
Wearable PC with an Artificial-Reality Helmet 20:20 Saturday 19 February 2005
Transgenic Mustard Cleans Up Soils 22:38 Tuesday 15 February 2005
Elektro, the Oldest U.S. Robot 16:35 Thursday 10 February 2005
Open-Source Streaming Translations in Porto Alegre 15:33 Monday 31 January 2005
RFID-Equipped Robots Used as Guide Dogs 19:35 Saturday 29 January 2005
Streaming a Database in Real Time 23:58 Friday 21 January 2005
Morse Code Used by Human Cells? 20:05 Wednesday 12 January 2005
Engineered Enhancers Closer Than You Think 20:54 Friday 31 December 2004
Transparent Transistors Are Coming 22:20 Wednesday 29 December 2004
DURL, a Search Tool for del.icio.us 14:47 Monday 27 December 2004
IBM Prepares 100-Terabyte Tape Drives 15:19 Sunday 26 December 2004
With Linux Clusters, Seeing Is Believing 16:47 Monday 13 December 2004
Self-Adapting Traffic Lights 19:07 Sunday 05 December 2004
Robotic Science Network Watches Our Oceans 23:32 Friday 03 December 2004

I think I speak for most readers here when I yell: SLASHDOT EDITORS, PLEASE, NO MORE LINKS TO RONALDS NO-GOOD BLOG.

Re:Yet another Ronald Piquepaille article

[Tongo]

Reviewing his posts to other articles, almost every one of them has a link to his blog in it somewhere. Sometimes his post contains nothging but "I posted this in my blog, here's a link". He doesn't seem to ever contribute anything.

This is a marketing strategy.

[TuringTest]

It's a well known fact that new technologies don't catch up until they can be used for pr0n.

Re:Dear god, not another one.

[CdBee]

If Slashdot editors really can be bribed to take a story, don't you think we'd see a lot more favourable coverage of SCO's lawsuits on here :-p

I may be wrong, but I doubt it's that simple.

Re:Questions

[godless dave]

To look at a cell using a microscope you have to take it out of the living thing it belonged to.

A real hit on the club scene!

[Muad'Dave]

Imagine getting some that fluoresce under 'black light' and putting those suckers in your epidermal/dermal cells! You'd be the hit of the club scene changing colors and glowing!

Re:Offtopic?

[Stile 65]

No, mitochondria use sugar to manufacture ATP from ADP, and other parts of the cell use the ATP to power their processes and thereby convert it back to ADP.

Also, only eukaryotes have mitochondria.

"Nano" everywhere!

[Nuffsaid]

How is this significantly different from the fluorescent marking techniques used for ages in conventional microscopy? It lasts longer? Big deal. Do calling things "nano" attract more funds/media attention? Sure! http://www.hardydiagnostics.com/Glossary-F.html

Re:"Nano" everywhere!

[cinnamon colbert]

in theory, the qdots ar more stable (less photobleaching) a recognized problem with std labels, and they have narrower emission spectra, so multiplexing is easier (eg std labels like fluorescein and rhodamine have wide emission spectra that overlap)(altho the lanthanide chelates have 10 nm fwhm)
potentially, you can tune the excitation and emission spectra to match your laser lines, so if someone develops a real cheap stable diode laser, you can tune the dot to that line
on the other hand, the qdots are big enough that they might not get to all the relevant sites.

Re:"Nano" everywhere!

[bodrell]

in theory, the qdots ar more stable (less photobleaching) a recognized problem with std labels, and they have narrower emission spectra, so multiplexing is easier (eg std labels like fluorescein and rhodamine have wide emission spectra that overlap)(altho the lanthanide chelates have 10 nm fwhm)

You obviously have never heard of BODIPY fluorophores, although I admit the admission spectrum is not quite as narrow as you describe. Multiplexing is easier with quantum dots, but you excite all of them at the same time. They have VERY wide excitation spectra, though fairly narrow emission. You are right about photobleaching; quantum dots are semiconductors, so don't ever photobleach. But some of the newer fluorescent dyes are pretty resistant to photobleaching. And the phycobiliproteins are amazing. The Terbium and Europium chelates have very long lifetimes; that's why they're special, not because of narrow emission spectra. It's time-resolved fluorescence, often used with FRET.

potentially, you can tune the excitation and emission spectra to match your laser lines, so if someone develops a real cheap stable diode laser, you can tune the dot to that line

So, you can't. The manufacturing precision is not good enough, and even if it were, there are "magic numbers" of atoms in these quantum dots, so you have a finite number of emission colors. Not that many, actually. The color depends on size, and size depends on the number of atoms. But again, excitation is not the problem; the dots have wide excitation spectra.

All in all, I think quantum dots are way overhyped. They are sticky, hard to passivate, and they blink.

Cancer cure in there somewhere?

[clambake]

So, if you could tag all the cancer cells with something that emits a beacon, then does that mean you could home in on them with a gamma knife and elimite them in any delicate part of the body with perfect accuracy?

Re:Cancer cure in there somewhere?

[merlin_jim]

So, if you could tag all the cancer cells with something that emits a beacon

There's a company that's working on an enzyme dye using jellyfish flourescence to do just that. This would work in theory even after it has metastized.

then does that mean you could home in on them with a gamma knife and elimite them in any delicate part of the body with perfect accuracy?

Forget gamma knife. Proton treatment is where it's at. Get radiation treatment for your prostate cancer in the morning, play tennis in the afternoon. Basically they create a 3D model of the tumor and modulate the proton beam's energy and shape (using a series of masks) so that the protons deposit most of their energy inside the tumor. There's a small amount that gets deposited ahead of it and none behind. Much cleaner/better than other radiation treatments. I've heard that with early diagnosis they're getting phenomenal success rates. And its outpatient.

Re:Offtopic?

[StateOfTheUnion]

No, mitochondria use sugar to manufacture ATP from ADP, and other parts of the cell use the ATP to power their processes and thereby convert it back to ADP.

Uhhh . . . in a word, no. Sounds like the complexity and accuracy a high school biology lecture . . .

Mitochodria oxidize Pyruvic acid in a series of steps to convert NAD+ to NADH. This produces CO2 and Acetyl CoA. Acetyl CoA is further oxidized in the Citric Acid Cycle producing more NADH and CO2.
What you may be thinking about is glycolysis . . . which is the breakdown of sugar (typically glucose) into pyruvic acid. This happens in the cytosol OUTSIDE the mitochodria. It is important to note that almost any carbon based molecule in the body can be converted into pyruvate and oxidized in the mitochodria (fatty acids, sugars, amino acids, some nucleic acids, etc.)

NADH is then converted into NAD+ through a mitochodria membrane to convert Adenosine Diphosphate (ADP) to Adenosine triphosphate (ATP) along an inner membrane of the mitochodria.

A more accurate restatement of your post might be:

Mitochodria oxidize pyruvate derived from sugar, fatty acids, amino acids, and other sources to produce NADH. Mitochodria also use NADH to convert ADP to ATP.

I think this is old stuff

[cinnamon colbert]

See, for instance, the quantum dot company (www.qdot.com). What is new is using a bio tag to direct the dot into the nucleus; such tags ("nuclear localiztion signals") are well known in theliteratrue for proteins, so what is new is that they took qdots and coated them with one of these signals. So, this is an addittion to the large catalog of optical probes that biologiest have.

Nanoprobes

[jhbradl]

I work in this field in graduate school and this technology is both old and new. The major problems right now are the toxicity on the cell. The actual probes can be modified or coated to exist within a cell without any major problems but when they breakdown, your body doesn't agree with some of the heavy metals that are released. As far as the word quantum goes, that only refers to the way that the electrons are confined withing the quantum dot. It is what gives the signal that you see. Safer particles are being synthesized and this field in the future will be used for drug delivery as well as real time visualization of cellular functions.