The team then smeared the yellow dye on a mouse’s underbelly, making the abdominal skin see-through and revealing the rodent’s intestines and organs.
The procedure has not yet been tested on humans and researchers will need to show it is safe to use, particularly if the dye is injected beneath the skin.
How did they resist the urge to sneak a peak at their own arm or one of their fingers?
When my little brother was 3 or 4 he stepped on a nail in our yard, probably dropped during some recent construction. It went all the way through his poor little foot, straight through, out the top. I can see it, vividly, in my mind's eye. Mom scooped us up and rushed us, still barefoot, to the ER. I remember him being almost calm- not the way I would have reacted. They x-rayed his foot and soaked it in a tub of what I now know to be iodine to kill bacteria. I remember this clearly: it was the first time I'd ever seen an x-ray in real life, rather than just in alphabet books.
Fortunately the nail totally missed anything important, so they just pulled it out and bandaged him up- no worse for the wear. He went on to be an honest-to-God track star so it obviously didn't have any lasting effect.
Decades later we were talking about something and he said to me, "Why don't they use that x-ray water anymore?". I had no idea what he was talking about so I asked him to elaborate.
The way he remembers the incident is that they put his foot into a bucket of amber liquid and, once submerged, his skin became transparent. He looked in and saw his own bones, blood vessels, and- in the middle of it all- the nail that was causing such a fuss. He described wiggling his toes, flexing his ankle, and seeing the bones and tendons move, directly, with his own eyes.
His toddler brain, probably in shock, had combined the x-ray film and iodine bath. Over the years it had grown more detailed and reinforced. He described it with such clarity that I almost wondered if I hadn't been mistaken. He didn't believe me when I told him how I remember it. We called our mom who confirmed my version of events, plus did some googling, which finally convinced him.
Anyway I just sent him this article. It's interesting that not only is the x-ray water he remembers theoretically possible, it would actually be amber.
That is a fascinating story.
Historically there were actually "live" x-ray machines, where you could have seen yourself wiggling your toes. They aren't used now due to the horrific exposure to x-rays, but before that was understood to be bad they were used in shoe shops (!). I don't know that they were ever used in hospitals though
I had a motion x-ray as recently as 2020. I don't know enough about the technology to know why this was different, but I have a copy of the video.
Edit: This is the type of machine it was: https://www.dmxworks.com/
That's cool. I wonder how they reduce the dose enough that it's safe. Presumably they were quite careful about how long the exposure was?
It took several minutes and a couple tries to get the exposure right on certain shots. They didn't seem overly concerned about the exposure. The person operating the machine didn't seem at all worried about it, so I didn't worry either. Can't rule out that I should have!
These days the machine itself should also warn if it's on too long, so perhaps the operator was relying on that. These days even UV treatment gets added to your record so that further treatments don't accumulate too much. Well, it does in the UK at least.
Digital x-ray sensors require a much smaller exposure than film, and I'd guess a lot smaller exposure than a shoe sizer machine, too.
For multiple exposures in motion, it will add up, but assuming there's a reasonable diagnostic benefit and the total exposure isn't too long, and the staff is well protected, it's a reasonable risk.
And of course the most harmed by fluoroscopes weren't the customers (bad enough) but the sales staff, who had multiple daily exposures day after week after month after year.
Checking your Wikipedia link: Yikes! These were used into the 1970s.
And of course industry denialism of any possible harm the devices might cause....
SMFH
1981 in West Virginia according to some sources.
Also used for medical research (e.g. back injury research)
I don't know why I'm replying to this other than to add another anecdote about the fungibility of memory.
I first saw a Macintosh computer around 1984/85 when I was 7 or 8 years old, and I vividly remember the color screen. They were demoing MacPaint or possibly a SuperPaint beta and I recall the palettes being in color. Except Macs at that time were black and white!
Now I realize that it was probably synesthesia where some of the gray patterns looked blue, yellow, brown or even pink. So basically it was like dreaming and seeing colors which don't exist. Although nearly all of my dreams are in black and white, and I only remember a handful of dreams that had color, like a recent one that had a fruit bowl with all of the colors.
https://en.wikipedia.org/wiki/SuperPaint_(Macintosh)
https://en.wikipedia.org/wiki/Macintosh_Color_Classic (hadn't been created yet)
https://www.youtube.com/watch?v=UVcv8ORSZEQ Color Macintosh Plus (mod)
https://www.youtube.com/watch?v=slY_F1MxGlk The Mac Plus had modern multi monitor support in 1986 and I got it working! (not me!)
I'm especially curious about the last link, because there's a remote chance that someone had a Mac Plus with a color video card that I was lucky enough to witness in a rare demo. But the odds of that are pretty slim. Maybe some old graybeard knows of such a thing.
Are you sure it was a Mac and not an Apple ][ ? I believe those had support for color at the time.
Well, he actually might have been perceiving what otherwise we don't perceive.
That's fascinating! I also have a vivid childhood memory that I can see, clear as day, despite knowing as an adult that it's impossible. It's really uncomfortable to combine the facts that a.) memory is unreliable, and b.) memory is what gives me my sense of self.
(if you don't accept that second fact, that's fine, I'm not here to convince anyone or debate)
At the moment, transparency is limited to the depth the dye penetrates, but Hong said microneedle patches or injections could deliver the dye more deeply.
Reverse tattoos incoming.
Sorry for being nerd, but your internal organs are going to get UV damage.
UV damage to internal tissues seems unlikely given that the tartrazine dye they used absorbs strongly in the UV region of the spectrum. You can see this in Figure S1 A & B:
https://www.science.org/doi/suppl/10.1126/science.adm6869/su...
Also the abstract of the article notes that strong UV absorption is likely a prerequisite for this effect:
We hypothesized that strongly absorbing molecules can achieve optical transparency in live biological tissues. By applying the Lorentz oscillator model for the dielectric properties of tissue components and absorbing molecules, we predicted that dye molecules with sharp absorption resonances in the near-ultraviolet spectrum (300 to 400 nm) and blue region of the visible spectrum (400 to 500 nm) are effective in raising the real part of the refractive index of the aqueous medium at longer wavelengths when dissolved in water, which is in agreement with the Kramers-Kronig relations. As a result, water-soluble dyes can effectively reduce the RI contrast between water and lipids, leading to optical transparency of live biological tissues.
https://www.science.org/doi/10.1126/science.adm6869
However this kind of research into the effects of absorption bands on the transmission properties at interfaces might ultimately bring about more effective sunscreen formulations.
UV damage to internal tissues seems unlikely given that the tartrazine dye they used absorbs strongly in the UV region of the spectrum
To expand: "the most hazardous UV radiation has wavelengths between 240 nm and 300 nm" [2]. While tartrazine has a lambda max at 425 nm in water [2], it has a second ridiculously-convenient peak around 260 nm [3].
TL; DR It should be mildly UV protective ceteris paribus.
[1] https://ehs.umass.edu/sites/default/files/UV%20Fact%20Sheet....
[2] https://pubchem.ncbi.nlm.nih.gov/compound/Tartrazine#section...
[3] https://www.aatbio.com/absorbance-uv-visible-spectrum-graph-...
according to this study, tartrazine can cause kidney and liver damage in rats
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5326541/
like an x-ray, I'd risk that for a one-off doctors appointment, but I'd probably not risk it on my body at all times. maybe there are safer dyes that have the same effect
maybe there are safer dyes that have the same effect
Given the effect is optical, perhaps encapsulation in benign, transparent beads? (Could be particularly effective is the goal is a tattoo.)
So that whole "get UV light inside the body to fight COVID" trope could come true? >smile<
If it dissolves in DMSO, penetration should be vastly improved.
What kind of application are you suggesting with DMSO?
t. chem student
probably mixing dmso with tartrazine and rubbing it on thin skin. dmso is commonly used as an excipient to promote dermal penetration (of the stratum corneum) by drugs in topical preparations
It is stated to be slightly solvable in DMSO, so that may be already enough. Anyway, i've got the impression - layman from reading some related articles - with DMSO the solubility isn't that important in the sense that DMSO seems to be temporarily increasing physical permeativity of the tissues - kind of creates micropores - so that even some not very soluble stuff can probably get through. I have a small bottle of DMSO at home, wonder if should buy some Doritos on the way home :)
"Alpha channel" dye.
Your immune system traps and isolates tattoo ink and prevents it from free contact with other tissues, so I don't see that working in practice.
I’m surprised that this characteristic of an extremely common dye—being used in its main application, as a dye—hasn’t been described before. Surely there’s some limitation that’s obvious to those skilled in the chemical and biological arts?
Or is it really just a matter of serendipity waiting til now to lead anybody down the path of trying it this way?
Given how common it is, it does seem weird that nobody has spilled it on themselves and noticed this effect.
The article says it's only to the depth it penetrates, so given that you have a lot of skin, comparatively, I'd guess it'd be hard to distinguish from the dye staining you weirdly for a bit.
Also, only specific wavelengths; from the article I don't think this is visible to the naked eye.
on this point curcumin aka tumeric has a quite a similar though not perfectly the same wavelength-adsorption profile (i.e. anything with a strong yellow color)
tumeric / curcumin is often used a magic skin treatment type dealie. question is why are not all these wanting-to-have-youthful-skin type people discovering transparency! answer is below but TLDR human skin is thicker and doses are still low.
some main points from the paper( damned paywell, see supplement) > the dye only goes about 1mm deep, so maybe that works magic in a mice but not so good in humans nor noticable. > the dye comes it at arnd 0.5-1 molar solution. gmw is 500 g/mol ish. so 1M solution is 500g in 1L or 0.5g in 1 mL aka 500 mg in 1 mL. Okay, fine, you prepare this and rub 500 mg on your big toe from a little 1 mL aliquot. the daily limit or whatever for the food dye is around 4 mg! Soooo... >on the latter point, safety, the supplement had a bunch of stuff where they were like "we did all the normal blood tests on the mice, and looked at the tissue, and looked to see if they died later, and it all looks good"
Makes me want to rub on some Doritos just to see…
Sorry lemon juice guy, you really should have rubbed Doritos on your face before robbing all those banks.
Maybe the concentration has to be high enough that this wouldn't happen often in practice? The point made below about mice having thinner skin makes sense too, though there are parts of the body where skin is quite thin, like ears and wrists.
I have a feeling that this will get tested by some intrepid YouTuber before the authors of the paper get approval from an ethics review board. I'll try to remember to Google this in a month or two.
>The point made below about mice having thinner skin makes sense too, though there are parts of the body where skin is quite thin, like ears and wrists.
Let's hope no-one gets it on their eyelids.
while smearing it on the rodent’s scalp allowed scientists to see blood vessels in the animal’s brain.
Since when do mice not have skulls?
Everyone knows skulls are transparent in everything except x-rays. It is known
Skulls aren’t transparent in visible light either.
I guess not only are skulls transparent to light but jokes as well. Went right through chuckle
Dead skulls, sure.
For live skulls, it's considered white rude to check.
Mouse skulls are very thin and you can sometimes image directly through them!
My thought too but later in the article it says that was by using the dye in combination with laser speckle imaging (whatever that is)
The article says they used laser speckle imaging for the brain test.
It says it's never been tested on humans and the proper diligence should follow,
But given that we already eat large amounts of it with no harmful side effects, the expectations are good.
The dose makes the poison. Considering that food usually don't make your tongue transparent [1], probably you need to use more than the usual amount to get the effect.
[1] Note that they get skin that is transparent only to one shade of red, it's not transparent to all the visible spectrum.
The absorbed dose makes the poison.
The effect of a substance is usually three orders of magnitude lower when you rub it on your skin vs. when you swallow it.
effect of a substance is usually three orders of magnitude lower when you rub it on your skin vs. when you swallow it
Going out on a limb and guessing you're at an effective dose for something when it's making your skin transparent.
(1) "All things are poison, and nothing is without poison; the dosage alone makes it so a thing is not a poison."
(2) assume it isn't absorbed into the larger body. Still the tissue absorbing it got a YUUUUGEEE dose. Then presumably most of it is washed out minutes later. So under that assumption we worry about localized tissue damage ---- --- which, if we're talking about things like cancer patients here who commonly get zapped with X-rays and gamma rays and antimatter and such, is perhaps not out of the ordinary. If there's no systematic damage the main concern would be cancer. If the skin dies, it can be fixed. And heck, a lot of cancer treatments also cause cancer i.e. many children with blood cancers go onto later get other cancers due to the medicinal cure of their blood cancer side effect.
eh i just put some on the top of my hand and i didn't see any bones
Tim: Look at the bones!
Maybe you should get that hand x-rayed. Is it particularly bendy?
what are we trying to achieve with making skin transparent? I dont see a use case. anyone want to help me with it? please tell me more about it.
Knee hurts, doctor can have a look and literally see what's wrong.
In addition to the medical usecases listed in the other comments, it's also just pretty cool.
xray can only pick up information up to a level.
an extra tool(window to our inner bits) without the necessity of making a biopsy is always welcome.
I can think of a use case. The same one we have for modified transparent Zebra Fish in medical research.
That is so that you can observe features such as the circulatory system.
https://en.wikipedia.org/wiki/Zebrafish#Transparent_adult_bo...
Diagnosing some internal illnesses without xray or MRI.
Truly wild. This could be an amazing advancement if true and safe!
I imagine it could eventually lead to a full invisibility serum, as documented in the classic Kevin Bacon film Hollow Man. Of course, we need to be aware of the side effects (mostly murderous rampaging).
Of course, we need to be aware of the side effects (mostly murderous rampaging).
Common side effects include rash, constipation, nausea, diarrhea, dizziness, homicidal urges, drowsiness, insomnia, headache, and dry mouth.
You forgot blindness. If you're transparent, your eyes won't be able to refract light. Which is good if you also have homicidal urges, but awful if you get diarrhea.
And would you get invisible diarrhea?
(This might be the more desirable of the two outcomes. Otherwise you the man may be invisible, but everyone sees your intestinal contents floating in mid-air.)
How would it get into bones? Wouldn’t the likelier outcome be visible animated skeletons, rather than full invisibility?
Absorbing anything that ends in -zine into the body does not sound safe.
I hope you don't have allergies then as you might otherwise be taking cetirizine already.
no it gives me headaches anyway
from Wikipedia:
Tartrazine is among six artificial colors for which the European Union requires products that contain them to be marked with the statement May have an adverse effect on activity and attention in children.
The FDA requires that the Precautions section of prescription drug labels include the warning statement, "This product contains FD&C Yellow No. 5 (tartrazine) which may cause allergic-type reactions (including bronchial asthma) in certain susceptible persons.
Never tested on humans
Some tropical American frogs evolved to do it naturally (fam Centrolenidae). Some fishes also can do it also in a few different orders (Siluriformes and Perciformes at least), so in lower vertebrates it is possible and evolved several times.
But they have a different metabolism than ours and a mouse skin is much more thin than our own skin. I assume that this effect will work only on very small animals and the optical effect will hit some thickness limit somewhere. Could work on fingers but not in heart. At this moment my hype level is a 4 over 10.
Never tested on humans
But a few billion have ingested it in the past year, sometimes even in medical pill form to make yellow pills. Could be worse at higher doses but seems plausibly safe and worth further testing.
The poison, as they say, is in the dose... just speculating but the quantity of dye ingested versus that used to render skin transparent may be such that the former is relatively innocuous while the latter would be very harmful. In particular it seems to be genotoxic at relatively low levels so that would be concerning for use in humans.
I don't recall the case of anybody grabbing a doritos bag and seeing trough their fingers, but a lamp behind your hand definitely can turn your fingers translucent. Maybe with both effects combined?
The more valuable contribution here is probably the idea IMHO.
To know that the optical effects of the light can be manipulated with the correct stuff and we could search for it. An ointment seems of to be useful to a restricted volume, to maybe the first millimeters of the skin.
We evolved totally transparent proteins that are hard, resilient and harmless. We have them in the eyes so we know how to do it. If we could only suggest the body to temporarily accumulate those proteins in the upper layers of the skin, or we could inject temporarily the proteins in local areas of interest that would be awesome (and maybe safe as long as is our own human protein)...
On the skin the continuous shedding of the upper layers would probably self-fix the stuff.
In Doritos? How are call of duty players not constantly transparent?
Their skin is transparent but cheeto dust isn't
Heh, like the superhero that can only go invisible if nobody is looking
Maybe their stomachs have been transparent the entire time, and no-one's realised. ;)
I’ve seen this movie. It doesn’t end well for Kevin Bacon.
Because the Graboids sense sound vibrations rather than sight?
6 degrees of Kevin Bacons translucence.
Halloween is about to become even more weird...
How long before someone tries to make a tattoo using this as ink?
"I need to go to the bathroom."
"Yes, I can see it."
Basically reverse sunblock. Ouch! I wonder how light affects internal organs. Skin is meant to be a protective barrier.
I don't think it's particularly bad for them, especially in the short term. In my extended family it's common to use red light therapy, which penetrates into the tissues to help the fight against inflammations, infections. It's also used as a treatment for dry eyes, which I also have. I may be wrong though, maybe common sunlight is more harmful with a translucent skin? Idk, it's interesting though.
Depends on the spectrum! Our insides don‘t care about visible light but long term sunny-day level UV light can not be good for them. This dye seems to be limited to red, visible spectrum, but you‘d need to test that first.
From the article, the dye is tartrazine -- FD&C Yellow 5 or E102.
Okay well getting yellow #5 on your skin definitely doesn't make you invisible.
Source: Doritos
Well, there may be something to it - get enough Dorito dust on you and you'll be invisible to the opposite sex.
I'm quite interested in how the use of tartrazine has been regulated around the world.
In my home country, for example, it's not permitted for use in food. Many other places, however, allow this.
Interesting, seems to be banned in at least 4 european countries (if i'm to trust a chatbot).
I just got my Doritos dry rub on, followed by a Sunny D Shower, and now nobody can see me.
Don't forget to go to Canada and get some Cheezies
Awesomest Halloween ever.
"I can tell what you had for dinner"
Paper: „Achieving optical transparency in live animals with absorbing molecules“, https://www.science.org/doi/10.1126/science.adm6869
Ah, it "reduce[s] the [refractive index] contrast between water and lipids, leading to optical transparency of live biological tissues." Craziest part being it was predicted using a classical optical model [1]!
Anyone want to sell me some tartrazine?
Don’t mice have skulls?
Halloween costume!
Some practical VFX artists are gonna go wild with this
I know they say "not tested in humans," but I don't think anybody's going to convince me nobody in the lab tried it out when they thought nobody was looking, unless there's some really obvious (to experts) reason to assume this won't work in humans.
introspective people eat doritos
This solves my Halloween costume for this year.
<s>Hey Tiktokers, who needs a stupid dye? Show your inner light. Swallow our new gastrosubmarine led pill and shit bright like a diamond.<s/>
Can’t wait till it becomes a trend on instagram
specifically tartrazine in only the red part of the spectrum. can this be real?
Wonder if this has potential for internal imaging too?
For example, with an endoscope or other thing that checks internal passageways. Applying this stuff (or whatever is appropriate to the given organ) could potentially allow the optical visibility of more stuff.
Huh, I never expected to find out that the Ghouls from Leiber’s Fafhrd and the Grey Mouser books were actually plausible.
(They were perfectly normal medieval fantasy humans, except for their flesh and organs being mostly transparent, so you just saw a pinkish skeleton with a faint shimmer around it.)
Some countries have banned it in humans, due to health concerns. https://www.verywellhealth.com/tartrazine-free-diet-83227
Strange dating moment:
"I really do have a good heart!" (takes off shirt, take out a bottle of dye, and smear it on torso) "See, just look at it!"
New kink incoming
I read a short story in my youth -- it must have been by Paul Jennings -- about a boy who got bit by a weird bug. His skin turned transparent and he had to go live in a cave.
Many years go by and he gets bit again and his skin goes back to normal. He finally returns to society, only to find that everyone has gone transparent, and he is once again an outcast...
It is fun to imagine how my intestines become transparent every time I drink Fanta and there is no one to see it but the microbes living there. Who probably "freak out" in their own way.
I wonder if this would improve Digital Optical Spectroscopy for cancer detection and monitoring?
Also related: https://www.ycombinator.com/companies/eden-2
Imagine this as face cream at a rave.
The Washington Post's headline for this article is:
Scientists use food dye found in Doritos to make see-through mice
My first reaction was, what the heck have I been smoking?
It's a food dye, if you can eat it you certainly can put it on your skin. And they probably did but don't want to announce that they experimented on themselves.
The dose makes the poison though. Tartrazine is already in cosmetics, but that doesn't mean a ton of it is still safe.
Another reason to avoid tartrazine. Who knows what its doing to our insides.
That isn't remotely what I was saying. You can die from drinking too much water, that doesn't mean you should avoid drinking water for fear of what it's doing to your insides.
$25 and an Amazon order and posterity awaits.
https://a.co/d/gJ1MQG3
Did the article imply you need red light to see the effect though?
Looks like someone took you up on it, instead of a showing a price the Amazon link shows out of stock.
That doesn’t always follow. There are (organic, large-molecule) substances that your mucus membranes will protect you from, and which you’ll then digest (denature) and greatly metabolize (non-leaky intestinal absorption routes through the liver) and so render harmless; but which would greatly harm you if left on your skin, as the substance can potentially absorb from there all the way to your bloodstream, without any digestion or a chance at first-pass metabolism.
Think, for example: testosterone gel. Eating it wouldn’t result in much if any testosterone entering your bloodstream — but rubbing it on yourself sure does.
blue #1 would like a word.
Also basic human biology: just because something's safe to consume (which keeps it isolated from the rest of your body until it's been through the digestive tract) in extremely low doses doesn't mean it's safe to expose yourself to a highly concentrated dose via external exposure.
You don't play with chemicals
Clearly you don’t know many chemists? You might as well tell EOD to not play with explosives!
confirmed as correct
Even if not intentional, such things happen by accident. Have you ever read up on how the psychedelic properties of LSD were discovered?
From https://en.wikipedia.org/wiki/History_of_LSD#Discovery
That's kind of how we got LSD, saccharin and microwave ovens. (not really "playing with" but not being super careful about safety)
Even when the play is "touching" and the chemicals are "food dyes"? I wouldn't say I'm a risk taker, but even I would probably try that out for giggles.
This is going to be a Halloween sensation if it ever becomes available to the general public!
It looks like you need special sensors and a lot of light in certain wavelengths. Would like to read the paper.
you'd probably get fired immediately for doing human experiments without IRB approval
"it was an accident!"