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

Dear god, not another one.

[Anonymous Coward]

This is turning out to be another "Hello and welcome to Slashdot, I'm Troy McLure^H^H^H^H^H^H^H^H^H^H^HRoland Piquepaille. You might recognize me from other blockbusters such as Raping Slashdot For Ad-Money and 10% Goes To CowboyNeal!"-day, isn't it?

-r

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:Offtopic?

[nyekulturniy]

If I recall correctly from my biology, mitochondria manufacture ATP from ADP, which powers our cells. They are remnants of prokaryotic cells which entered into a symbiosis with their eukaryotic hosts. Mitochondria have their own RNA, which is passed from female to child in sexually-reproducing prokaryotes (and, despite the childish comments, includes Slashdotters).

I hope this clarifies why a mitochondrion is important.

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.

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:Questions

[godless dave]

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

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: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.

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.

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:"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.