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So how much more expensive is the second, "smoothing" phase than the original production phase?

It's another wet-chemistry phase. It's no more expensive than the first synthesis step. But each step of course adds to costs (in terms of manpower, chemicals needed, etc.).

Similarly, adding the lipid layer is just a a ligand exchange: you mix the quantum dots with ligand in the right solvent mixture and they become coated. Simple in principle, not too complicated in practice, but it adds another step to the process.

how much do the products of each of those phases currently cost

Quantum dots are fairly expensive, but they are similar in cost to speciality chemicals that don't have industrial uses and thus don't benefit from economies of scale. Some examples from companies that currently sell quantum dots:
Invitrogen 4 ml of 1 micro-molar QD solution (~15 mg of qdot solids) for $335 ~ $22 million/kg
Sigma-Aldrich CdSe QD, 5mg/mL, 10mL solution for $399 ~ $8 million / kg
SpectrEcology 50 mg CdSe/ZnS QDs for $449.00 ~ $9 million / kg

For comparison, ubiquitous chemicals like gasoline are ~$1/kg, common chemicals like acetone (reagent grade) are ~$30/kg, high-purity semi-rare materials (e.g. pure selenium) are ~$1,000/kg, and speciality chemicals (for which there is no industrial need) are typically $100-$1,000 for a 500 mg quantity, which means $1 million / kg. As you can see, it is much more expensive to synthesise a speciality chemical (basically requires a trained chemist to manually do a small-scale lab synthesis for each batch), as compared to industrial-scale manufacturing.

There's no doubt that quantum dots could be made more cheaply if there were a real need for them. There are huge challenges in terms of how to scale-up the synthesis, but nothing that couldn't be addressed with clever chemical engineering and automation.

This is like turning gold into lead.

Dr. Mironov has taken myoblasts -- embryonic cells that develop into muscle tissue -- from turkey and bathed them in a nutrient bath of bovine serum on a scaffold made of chitosan (a common polymer found in nature) to grow animal skeletal muscle tissue.

He's turning bovine serum http://en.wikipedia.org/wiki/Fetal_bovine_serum which costs about $800 per kilogram, http://products.invitrogen.com/ivgn/en/US/adirect/invitrogen?cmd=catDisplayStyle&catKey=100301&filterDispName=Mammalian+Cell+Culture&filterType=1&OP=filter&filter=ft_1701%2Ff_188301*&_bcs_=H4sIAAAAAAAAAMWQ22rDMAyGn8Y3CwlODFt6maWklMIY67Z746iJwYfgQ0LefvK6lrGV3Q6EfiRb%0A8vc7Lwmtn53towg%2BI9V9dgQ3SwH%2Bj%2F4YwkRYQ6oOY1mWQppZBmcHMIWwGpteBkCJHhMYTKPVqXHZ%0AmHPT59eNVddMk5KCB2mNL8agFb5CKpaC1sFFSDV9oCglLXFgs0G9w7IFpbI2qhAdJE6uEe0xe3Xc%0A%2BBOItDF7AY5o4Rf69EXzk581NcVjOQ%2Fmwv92xMR76XBlOroOENYJ3RO23b%2FvntDBVvpJ8bXlAQbr%0AViTC5gFWvPHJ%2FN3YiSt%2F2xlqSSk7W8R%2Fivqf2c80t%2BA%2FAApkysVCAgAA into meat, which sells for about $5-10 a kilogram.

Bovine serum is a byproduct of the commercial meat industry. So he first has to farm the animals, and slaughter them, to get the serum, to grow a much smaller quantity of meat.

Discarding ethidium-bromide and acrylamide gels?

If I were doing DNA gels at home, I'd be using sybrsafe. As the name implies, it's a lot safer. Also less damaging to the DNA I'd be trying to isolate and can be reused many times. Slightly more expensive than dirt-cheap ethidium bromide though.

While unpolymerized acrylamide is a pretty dangerous neurotoxin, a polymerized polyacrylamide gel should actually be pretty safe. Granted, I wouldn't trust it, but plenty of academic labs do throw their in the garbage.

Biological experiments are different from software development, they need follow up and supervision through the end, which may take 2-4 days.

Some do, yes, but I'd say that doesn't describe most biological experiments. There are times when I need to work for half a day without interruption, but those are rare.

How do you discard biohazardous materials and mutagen/teratogen substances at home?

Depends on the hazardous/mutagenic material. There are quite detailed protocols and guidelines for disposal of almost all waste coming out of labs, with a little thinking you can find facilities to dispose of it, or find a way to neurtralize it yourself. And it's not like all research requires working with plutonium or exotic and dangerous materials. The most common teratogen I'd probably pour down the sink or drink (the most common teratogen being alchohol.)

Same here. Microsoft's virtual desktop power tool crashes Vector NTI reliably, which makes it entirely useless for me.

Very good question. These are not just dyes--they're fluorescent dyes. They absorb a photon in a certain energy range, which puts and electron in an excited state. After a certain amount of time in that excited state (i.e., the "fluorescence lifetime") the electron drops back down to the ground state and emits a photon of lower energy (the difference in energy between absorbed and emitted photons is called the Stokes shift). Every time an electron jumps to that excited state, it can potentially react with an oxidant and destroy the fluorescence (this is known as "photobleaching." If you mix antioxidants with the dye solution you can decrease the rate of photobleaching--such an antioxidant solution is called an "antifade." There are other ways to reduce photobleaching, such as sticking certain chemical moieties onto the dye.

In short, the stability of the dye system really depends on the dye structure and the presence (or absence) of oxidizing molecules. There are plenty of fluorescent dyes used in lasers, but I don't know how long they last before bleaching. If the dye is in the right solvent (such as DMSO, perhaps) it might take a damn long time to bleach. But the point is that dye is cheap compared to refined silicon, and replacing bleached dye might be as simple as flushing out the old stuff and pouring in a new solution.

In my opinion there are only two reasonable long-term solutions to solar energy production: 1) Imitate photosynthesis using fluorescent dyes. 2) Let the plants do all the hard work of turning photons + water + carbon dioxide into sugar, then figure out how to imitate cellular respiration and turn sugar into energy (specifically, a separation of charge).

This site has tons of information about various fluorescent dyes, though it's geared towards use in molecular biology, not photovoltaics (unless you count the voltage-sensing dyes).

word

Also, I'm a biological scientist. A very common piece of software we use is a suite called Vector NTI. There has long been a Mac version (not sure which platform was first supported). 30% of those in my field are Mac users, maybe more. When OSX came out NTI wouldn't run on it. Now, it will only run well on Jaguar and nothing newer, and that's just a recent development http://www.invitrogen.com/content.cfm?pageid=11368 and even then I know people who say it doesn't run well. So after four years they can't get their software to run on the platform that a substantial percentage of their customers use. Why? Then you get a statement like this:

"Mac OS X's UNIX-based architecture provides the power and stability for working with vast amounts of data for scientific research. Vector NTI® Suite is a tremendous addition to the growing number of life science applications on Mac OS X." Ron Okamoto Apple's Vice President of Worldwide Developer Relations

NTI has never run on Unix. It hardly runs on OSX. That's a misleading statement. I grew up on Macs. I expect better than this from them, or should I? I just scratch my head at the Mac is better mantra. Better at nothing I've seen to justify a switch (except Expose - that's awesome), just different (and prettier for sure).

From the article "Time-lapse phasecontrast and fluorescence images were collected from cells grown on glass coverslips using a Zeiss Axiovert 200M microscope equipped with a Hamamatsu ORCA camera." They use a fancy (and expensive) inverted light microscope with a digital camera attached to it to take the images. The section on the right part of the movie is made using with a fluorescence stain as the cell proceeds through mitosis. There is a light source attached to the microscope that emits light at a certain wavelength to excite the fluorescence stain that can be bound to a variety of things - mitochondria, DNA, etc. In this case the fluorescence is bound to alpha-tubulin-GFP. Alpha-tubulin is a protein found in microtubules which are involved with cell shape and cell structure. GFP merely means "Green Fluorescent Protein" - that it will fluoresce in the green wavelength. http://microscope.olympus.com/contentsDB/01world/0 1reseach/a_appli/12/contents.html Use of fluorescence in biochem is really fascinating, and fortunately I have a good amount of experience as a student using fluorescence as a tool. You can bind several fluorescence probes to a cell and get some really cool images: http://probes.invitrogen.com/servlets/photo?fileid =g002761&company=probes

Although it is mainly protein oriented, there are several molecular tools available at ExPASy that I use a lot.

Also, VectorNTI is now free if you join their user group. It's a really powerful suite for plasmid design and molecular analysis.

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

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

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

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

Heck, don't we all have our own mail-order suppliers for gene sequences?

If you've got a credit card and a mailing address, you certainly do have your own mail order supplier for DNA sequences. In fact, you've got quite a few to choose from.

and I can tell you that this story is not in any way 'new' news. Maybe the nano blurb is a new idea for this technology, but the idea of turning on and off engineered genes at you're discretion is not.

The system they are referring to is known as a tetracycline responsive promoter. A commercially kits for this purpose are available here.

Having used the system, I can tell you it does not work very well. A better system is located here and an even newer system here. I rarely post here, but I have noticed that most of the pieces on biologically related topics that make it on /. are not well researched on the poster's part. When I think about it, the majority of news and pseudonews sites on the web and in the traditional media fail miserably when producing stories about science in general and particulary regarding biology.

Yo

and I can tell you that this story is not in any way 'new' news. Maybe the nano blurb is a new idea for this technology, but the idea of turning on and off engineered genes at you're discretion is not.

The system they are referring to is known as a tetracycline responsive promoter. A commercially kits for this purpose are available here.

Having used the system, I can tell you it does not work very well. A better system is located here and an even newer system here. I rarely post here, but I have noticed that most of the pieces on biologically related topics that make it on /. are not well researched on the poster's part. When I think about it, the majority of news and pseudonews sites on the web and in the traditional media fail miserably when producing stories about science in general and particulary regarding biology.

Yo