00:11
Hello Len. Hello Asami. How are things? Things are fine. Although our usual clap at the beginning, I was a little worried.
Why? I forgot to mention this beforehand, but I was at a community orchestra concert earlier.
And of course, with all of those things, you end up clapping for about half the time.
And so my hands at the end of that were sore. Oh my god, was it? Were you clapping so hard?
Well, I mean, a buddy of mine was also playing in it, right? So there were parts where I was definitely clapping hard.
But, you know, right? It's not just here, but I do feel like at a lot of events that I have been to here,
from high school graduations to these sort of orchestra music things, that I find myself clapping a lot.
And that my hands are just like, I'm like, I'm done. Like, I want to celebrate you, but also like, I can't clap anymore.
Like, there's like, I'm running out of clapping ability here. This needs to end.
You know, not every clap needs to be audible or like smacking your hand, destroying your skin cell level of, you know, intensity.
You can just clap like a normal person and still make a noise.
What do you mean? This is not, no, no. If you lightly tap your hands together, you don't make any noise.
There's no noise to be had there. A clap is only at like, at least 60% power, right?
Like, you gotta really commit to the clap.
Something tells me that you're like, really clapping hard.
Look, I've had to tone it back since I've been here because of this issue, right?
Like, you know, I mean, you look, you know, or at least you have the awareness of what like a Japanese high school graduation ceremony is, right?
It's basically like 15 minutes of straight clapping as people wander into the room to fill the seats and then wander back out in the end.
Both of those is like 15 minutes of people trying, trying to lightly clap their hands while still making enough noise to like generate a clap, right?
Shit like this. Oh, excuse me.
Yeah, I mean,
Why are we talking about clapping for three minutes?
I mean, I could, I could go for 10. You want another episode out of this?
No.
All right. Okay. Well, then I'd like to talk about something much more fascinating, but actually also having, also having to do with skin.
So that's, that's a related,
That was an unexpected segue.
It worked, right?
It worked. Okay, sure. Go ahead.
Sure. Sure. She says.
Yeah. So I had to come across via the, you know, random assortment of algorithms that toss things at you.
03:03
The suggestion, because I take all social media things as suggestions until proven otherwise, that apparently a particularly common substance could be used to turn skin transparent, which is odd, right?
So we don't need zebrafish anymore?
Well, I mean, not yet. I think this, this isn't like a perfect process.
And nor does it just.
Well.
But it sounds like a certainly click baity.
It's certainly click baity, right?
Science article.
Yes.
So where did it take you?
So I clicked on it and it brought me, well, I think there were a couple of options, but I went to the triple A S, you know, science websites.
SCICOM discussion of it.
And this was back in just September of this year.
And it is a fairly easy, pretty reversible approach to making skin transparent so that you can do things like observe the internal organs of an animal.
That sounds wild.
Yes.
With the caveat and a strong caveat here, a dead bird app creator known as like something it's like research in mice would be proud of this one, right?
You can do all of these things in mice, right?
So this is tested in mice, right?
Yeah.
With this caveat.
I'm glad that people haven't just like decided to do this on humans casually.
No.
However, we, I guess, technically do it accidentally to ourselves.
I haven't had this thought yet.
Oh, it's that common.
Yeah.
Let's get to what it is, right?
I'm going to stop beating around the bush.
I'm going to stop like throwing the lead.
Yeah.
Get to the point, Len.
Get to the point, Len.
So what it is, is a compound or a chemical called tartrazine, I believe.
Okay.
If I'm describing that, if I'm pronouncing that right.
And tartrazine is an orange dye.
And this orange dye is what is used in, maybe listeners can try to guess what they think it's found in, two things.
Things like Cheetos or Doritos.
I believe both of them contain tartrazine.
This science article, which we'll probably link, is, it mentions Cheetos first, but then later it does in fact mention, quote,
so tartrazine is approved by the U.S. Food and Drug Administration and is used to dye a range of foods, including Doritos and Kool-Aid.
So the researchers expected it would be safe to use in biological tissues, end quote.
06:04
So, yeah, this works, right?
To jump right at it, they were able to shave the hair off of a mouse, like the belly.
And they were able to rub the tartrazine onto the mice's belly and get a visual like transparency.
Yeah, crazy, right?
Yeah.
I mean, like, okay.
Being a good chemist, I had to look up what tartrazine molecular structure looks like.
Very good, good chemist.
It does look like a very strongly absorbing molecule, given that there are like two benzene rings attached to it with a lot of nitrogen-nitrogen bonds,
both double bond and sort of 1.5 bonds around.
So there are lots of, I think this is a type of azothiase.
If I recall my organic chemistry, yes, it is an azothiase.
I'm looking at it now and yes.
And double bond and a sandwich with some kind of resonance availabilities are called azothiase.
And they do like, you know, they're very found, commonly found type of, you know, both like skin and I think consumption safe type of dyes that exist in our daily lives.
And I'm just checking it out.
Yeah, it looks like there are lots of places where light can be absorbed.
You know, lots of possibilities.
So just looking at the bunch of benzene rings and double N bonds make me think, okay, this looks like a very strongly visible range absorbing molecule.
Yep.
So that's what I'm getting from the structure.
And yeah, you're right.
These are used in like food, soda, candies.
The Wikipedia article I found for the tartrazine molecule also notes that it's used in dyes for dyeing eggs for Easter.
So it's because it's just a dye.
Okay.
So like very, very safe.
Yeah.
Yeah.
It's just fine.
It seems like they tend to give this like bright yellow color.
And I'm guessing that it's one of the bunch of different food dyes that Doritos and Cheetos use.
Yeah.
It's probably one of the major ones.
Right.
With that sort of, you know, yellowish coloring.
Orangey.
Right.
Right.
Exactly.
And your chemistry or chemist intuition is spot on.
Just based on even the SciComm science article, not even the research article yet.
They note that the dye absorbs blue light.
And so.
Well, hence they appear yellow.
Right.
Hence they appear yellow.
Right.
These are the sort of expected, at least for these types of dyes, I will leave as a small caveat and exercise for the reader.
09:06
If they wish to dive into how things appear, certain colors, it becomes complicated.
But anyway, not important.
Okay.
This particular thing.
Right.
This dye absorbs light and it absorbs individual spectrum.
But what's important here is, from my understanding, that this also.
I'm looking at it, so it's hard to reframe it.
Quote, reduces the refractive mismatch.
So basically within your cells and like all of the sort of skin layers.
We've got water.
We've got lipids.
You know, we got all these things hanging around in there.
All of that refractive mismatching is what bends light everywhere.
And you get an opaque substance.
Right.
That's the cause of scattering.
Yeah.
Hence why things appear solid to us.
Yeah.
You know.
Great.
So, right.
So there it is.
But in this case, you can essentially like.
I see.
Take in the dye and the dye acts as essentially a smoothener for that bending effect.
Right.
It reduces that really strong bend.
And now the scattering gets reduced.
And so at one point, apparently it's red and orange light.
They get allowed to pass through without scattering.
And so you end up getting, you know, a transparency with essentially those forms of light.
Yeah.
And maybe our skin naturally contains a lot of these, you know, orangey red type colors.
Just inherently to our lipid layers.
And maybe reducing the mismatch of that gives us some level of optical transparency.
Yeah.
And so that is.
It is kind of crazy what they were able to see as a result.
Right.
Because this is a very, very simple sort of physical mechanism.
Yeah.
But no one would have thought about rubbing Doritos to mouse belly from this article.
Yeah.
It looks like.
And like.
Yeah.
Transparent.
I mean.
This is fascinating.
I love that you picked this article up because, you know, I love optics.
And I'm actually looking at the research article and just like skimming as we speak.
But.
Yeah, it's.
It's.
Okay.
When I say like transparent, they're not like a zebrafish transparent.
Right.
No, no.
This is.
It is specific wavelengths.
Right.
So that's that red orange.
And for anybody who's interested, the Science AAAS site has a short video of this.
So I don't know if you've seen that on the page, but there is a short video of the transparency
12:01
of a rat's belly.
So that is something that you can see visually there, but you're, you're pointing it out.
Right.
Oh, and it looks like they've tried a whole library of these azo dye type molecules.
Oh, neat.
Okay.
In the paper itself.
It's not just tartrazine, but I guess these are all family of tartrazines.
That makes sense.
Because they have the structure of, you know, the N double N bond sandwiched between some
kind of ring or, you know, double bond network that lets you have the resonance to absorb
the visible color range light.
So well, some of them can be quite large, like huge macromolecules.
I mean, like, I mean, talking, talking like a physical chemist, really, because I feel
like anything more than like, 12 atoms are big, but if you talk to like a protein, you
know, people, you know, 12 atoms are like, might as well be water kind of thing.
What's this dust?
This is just like, yeah, what is this insignificant dust?
Somebody clean like the palette.
I don't know.
This is weird.
Yeah.
Oh, but yeah, okay.
I mean, like, yeah, I'm not I'm not reading every single like, you know, things about
it.
But it looks like they have done pretty thorough experiment on measuring different oscillator
model that like, you know, actually accounts for this matching the refractive index matching
mechanism.
Okay.
And they have done a lot of like a UV viz type experiment across and they've done even
like two photon microscopy, three photon microscopy.
So like, a lot of Wow, a lot of, you know, experiments, so not just like the catchy like
I robbed Doritos and mouse became transparent.
Yeah.
It looks like it looks like they've done a lot of experiments to support this claim.
I am not finding well, okay, that's that's a lot.
I'm not fine.
And they've done like a concentration studies, right, okay, interesting, but I'm not finding
at least not easily like a place where it says if it's reversible, or if it's like a toxic
level of Yeah, intake, like, you know, because because every sort of these kind of FDA approved
molecules come with like a toxic toxicity window.
Yeah.
So, uh, yeah, it's something like that.
Yes.
Yeah, like, like, basically just a range at like, okay, at this level of concentration
under this time, you know, things can be toxic, like water, when consumed in an immense
amount in a short period of time could be toxic.
Yeah, it's just that it's like, usually given how big our mouths generally are, there's
only so much water you can intake in such a short period of time.
15:01
I refuse to be limited.
I mean, you could just like reverse osmosis and blast yourselves out is what it's saying.
Oh, man.
What a terrifying.
That is a terrifying way to go.
Yeah.
Yeah.
But anyway, that that horror story aside, yeah, so I'm kind of curious, you know, like,
if if this is a reversible process, or if it's Yeah, because, because, yeah, actually,
I do need to read this properly to know but if it's a multi photon process, then it's
likely that, you know, it would only become transparent while the enough light has been
irradiated to the system.
And then once the radiation is over, it kind of like slowly goes back to right, it's non
transparent state, which could be an interesting application on its own.
Yeah.
This is potentially really cool.
Me not being biologists, so take it as a big, big grain of salt.
But like, this means that we might be able to have a whole slew of test animals.
So there are, you know, several sets of animals like zebrafish, or like, what's the worm's
name?
Oh, dear.
It's E. elegans or something.
Yeah, elegance, C, C elegance.
C elegance.
Is that right?
Yeah.
It sounds like a bad joke.
Yes.
C elegance.
Okay.
These are these are the round worms, right?
Like, anyway, these are like, favorite test animals for biologists for neuroscientists,
etc.
Because precisely for that optical transparency properties, like they're transparent to our
naked eyes under ambient light, or, you know, normal lighting condition, like a white light
lighting conditions.
So and that's why we can see internal movements of organs, other things, and we find that
useful.
Yeah.
It's also easy to market, like a specific part in like a fluorescent dyes.
And you can specifically track that fluorescent marker, optically and visually.
And this is huge, because especially with the improvement in imaging techniques that
we have now, that doesn't have to be billions of dollars anymore, you know, a lot of people
can have a good camera hooked up to a decent microscope, and you can do a very good video
of like fluorescent dye tracking of cells and whatnot.
And so so being transparent, like we chose them out of, I guess, convenience, right?
18:01
Because they were naturally optically transparent.
We found them.
So yeah, if we can purposely make them transparent, without, you know, ruining the entire organism,
right organism or animal, well, yeah, yeah, I guess all animals are organism, we're not
going to get into the part where we like, you know, call human participants.
I am not a biologist.
I'm just saying I don't want to get into the discussion because it is an important one
about like, basically deeming your subjects as like, subjects or materials to your experiment,
or whether you actually treat them as living creatures.
Okay.
So like, more of, yeah, like area of research that I am less, that's just, I'm least credible
to talk about, because I have never done animal research in my life.
Not even worms, or like anything, anything, no, nothing alive, like, same.
I didn't even use liquid most of my life, like in my research life.
I did use liquid.
But I see how far removed you are in that case.
So yeah.
So I'm not qualified to talk, you know, what's, what's, what's an animal and what deserves
a ethical research method, etc.
But yeah, yeah.
My point is, that was a long way to say, there is a group of animals that are naturally transparent
that we like to use them for experiments.
And if we can do this in a safe way, relatively, like ethically safe way, and in a way that,
you know, we can turn other test animals like mice, or some other form of non-transparent
test animals, you know, if we can make them transparent, potentially, we gain more information
out of this.
Right.
Yep.
So, cool.
I don't know.
Like, now I have to slightly worry about eating Doritos and Cheetos, I guess.
So I guess this comes back around to why I said it was possible that we accidentally
have done this, right?
Because when people eat Cheetos and Doritos, what do your hands look like in the end?
Right?
They're just covered in like, that sort of like, orangey dust type thing, right?
Now I'm pretty sure you have to like, sort of absorb it, like it has to be like in the
skin.
Yeah.
So I'm looking at one of the figures and for, and this is like microscopic light, like microscope
setting.
So it's not at all relevant to our normal daily lives.
We also have a lot thicker skin than what they were testing on, right?
But they're looking at, so there's a figure of increasing, it's like a tile of images
with on one axis is a constant increasing concentration of tartrazine and on one axis
is like different types of light source.
Okay.
Right.
So it's like white light, green light, red light, etc.
21:00
And, uh, the transparency and like, um, blurriness begins really prominently around, I would
say 0.47 molar, which is pretty concentrated, I think.
So I am like, it's safe to say that we're not consuming enough tartrazine in Doritos
or Cheetos to make ourselves transparent from the inside all of a sudden, or have like,
you know, invisible hands or fingers after eating a bag of Doritos.
That would be such a wild experience though.
That would be a wild experience.
I think that would be the way for Doritos to sell themselves in like next Halloween,
maybe.
Yeah, that'd be it.
Be like, we've upped our concentration.
We've upped our concentration of tartrazine.
Have a ghost bag of Doritos.
Oh my gosh, should I get paid for this idea?
I'm not sure.
I'm not sure just because that probably does push into the danger level of consuming that
much diet.
Yeah, yeah.
You will probably, you will probably significantly seriously harm yourself before you can have
fun having transparent fingers.
Yeah.
So don't do it, kids.
Don't do it, kids.
Don't, don't eat 20 bags of Doritos with hopes that you'll become translucent.
I mean, 0.47 molars though, like, I don't think 20 bags will cut it.
Like, you would need to eat a lot more than that.
Yeah.
I'm not, I'm not going to do the math right now.
Maybe I'll do it later and like give myself some horrifying consideration of how much you'd
have to consume.
But yeah, I mean, you'd, it would probably be easier.
Any high schoolers listening to this can do the molar concentration calculation.
Yeah, somebody else do this.
Figure out how many moles.
I don't want to do it.
How many moles of tartrazines are required.
Yeah, it's not that hard.
One thing that this tile of image doesn't show or I have not figured out is like the
thickness of the layer.
So like, I don't know, you know, like what the bases are.
Right.
So I don't know.
That aside, it's a pretty fun thing to talk about, I guess.
Like it's a very eye-catchy headline for sure.
And I think it's a cool way, like, I think food chemistry is really cool because it reminds
everyone that chemistry is indeed everywhere.
It's I guess.
I find that people, people think it's more interesting if I talk about chemistry of baking
more than like, you know, two-photon ultra-fast molecular dynamics.
So there are, it's because it's relatable, right?
Like ultra-fast molecular dynamics is, yeah, but it's not relatable.
Yeah.
But thanks for bringing this up, Len.
Yeah, you're welcome.
This is really fun discussion.
Yeah.
And yeah.
I look forward to it.
I'll link the show notes, like link at least the SciComm articles to the show notes.
And it does not look open access, this paper, so you would need some kind of access.
24:05
Listeners.
Yeah.
Cool.
Yeah.
All right.
All right.
Looking forward to Rita's.
Yeah.
That's it for the show today.
Thanks for listening and find us on X at Eigo de Science.
That is E-I-G-O-D-E-S-C-I-E-N-C.
See you next time.
