Alabama STEM Explorers is made possible by the generous suppor of Hudson Alpha Institute for Biotechnology Southern Research Solving the world's hardest problems the Holle Family Foundation, Alabama Works Alabama STEM Council, Alabama Mathematics, Science, Technology and Engineering Coalition, Alabama Math, Science and Technology Initiative.

Hey, guys, I just got some really cool letters from some viewers.

Hmm.

Wonder who this is from?

Magic Tea kettle, ransom note Anderson, I'm holding the magic tea kettle hostage you have until midnight to pay me $100 or it's mine forever.

I don't have $100.

We're going to have to solve this crime another way.

I think, Kathryn I'll know what to do.

I think we need to find her.

Come on.

Thanks for joining us on today's episode of Alabama STEM Explorers.

I'm Katherine and I'm Anderson, and we are at Southern Research in Birmingham, Alabama.

But you might notice our lab looks quite different than normal.

It is an official crime scene because there has been the ultimate crime committed.

So Anderson was walking in today to show me all of this fan mail that he's been getting because he is quite famous.

And then tell him what happened.

Well, I walked in.

I saw the note one note, the ,,, ransom note, the ransom note.

So somebody has come in, they have broken into our lab and they have stolen the magic tea kettle.

Anderson is pretty upset.

I'm pretty heartbroken, but that is OK. We are going to go through a series of laboratory experiments and we are going to try to figure out or who who stole this tea kettle.

So first thing, let's look at the evidence that we have and our potential suspects.

So the evidence is the ransom note and the envelope that it came in.

And then the person who stole the tea kettle also left behind a soda can.

And then for our potential suspects, I think it's safe to say that we have three Lydda Andrew and Lawson, each of these suspects left behind or sent Anderson fan mail letters.

So what we're going to do is we're going to do a couple o experiments and see if we can figure out if one of these fans is the same person who wrote the ransom note.

Sound like plan?

Definitely.

All right.

So to narrow down the suspects, the first experiment that we were going to do is called paper chromatography.

And the way that this works is it is going to help us determin if the black marker that was used to write the ransom note is the same black marker that was used to write one of these fan mail letters.

And the cool thing about paper chromatography is that it is going to separate the colored pigments that make up the black marker.

Because black markers are not just made up of black pigments, there's a lot of different colored molecules in different colored compounds that make that black market marker.

But paper chromatography is going to allow us to separate these colors so we can see a difference.

All right, cool.

Yes.

So every marker company has their own sort of secret recipe And when I say recipe, I mean, they have their own secret a ratio of different colored pigments that they use.

So not every black marker is made up of the same colors.

All right, you ready to do the experiment?

I'm definitely ready.

OK, so the first thing that we're going to do is if you want to pass this scissors over here.

So we're going to cut these letters very carefully.

What we're going to do is we just want to kind of cut a rectangle where that eye is at the bottom.

And this is going to be our sample.

OK, so Anderson, I have finished cutting the paper from our fan mail letters and from the ransom note.

And we've also taped the paper to a glass rod.

And the way this experiment is going to wor is at the bottom of each speaker I have what is called a solvent and a solvent is just a liquid that can dissolve other substances, and in our case, our solvent is water.

And so some people use you can use ethanol rubbing alcohol, you can use methanol.

It really depends on on the experiment that you're doing in the mixtur that you're trying to to dissolve.

So what we're going to do is we're going to take our samples We are going to put it into the beaker just like that perfect.

So in other words, we're going to use solvent to solve the mystery.

You're good, Anderson.

OK. And that's OK.

Perfect.

And so now you can see it.

So this process is going to take about about 30 minutes, maybe 20 to 30 minutes.

But what you'll start to see is you'll start to see a beautiful color banding pattern that's going to come up from that black ink.

It's going to be really, really pretty.

And you can kind of think about this as as like a race show in a race.

There is a start line, which will be that black ink at the bottom of the paper.

So that black line is in that line.

There were a lot of different colored chemical pigments that are in some undefined mixture, and it's just the same way how there's a lot of runners at the beginning of a race, like at the beginning of that starting line of a race.

And so when the race starts, they're going to spread out pretty quickly because they have different abilities and they travel at different speeds.

And so in the same way, these chemical compounds in thi in this mixture, they also have different abilities and they're going to travel at different speeds.

And so as this solvent moves up that paper strip and as it travels upward, it's going to dissolve the.

Mixture of chemicals, and it's going to pull them up the paper and so that chemicals that dissolve the best are going to travel further.

The chemicals that don't dissolve as well are not going to travel as far.

And then there's a separate component because some chemicals have a greater affinity to the actual paper.

And so those will want to bind to it.

And so they'll stay a little bit closer to the bottom because they don't want to.

They don't want to give up that relationship with the pape and kind of think of it like that.

And so it will take them longer to go up the paper.

This is the same thing, like if you and if you've ever written a letter and you accidentally spill a glass of water on that paper with all of that ink, it's the same principle.

And I don't know if you've ever seen it smears and you see a lot of different colors.

The only way I thought my poem was black is the same thing that's going on, and this is an experiment you can actually try at home.

You want your paper to be sort of porous.

And when I say, of course, that means something that is not glossy, something that can kind of absorb ink.

So a coffee filter works really well.

So try it.

Try a couple of different black pens, a couple of different blue pens out on a coffee filter and see what?

See what you get.

All right.

So it looks like our experiment is complete and we can look at these four different chromatogram.

That is what it is called.

Once it is done and so you can look at it and you can see the different colored pigments have separated really nicely.

And so of the four, which suspect do you think that we can eliminate?

I'm going to have to say Lawson I definitely agree with you, Anderson.

I think it is a safe assumption that Lawson the pin that Lawson used to write his fan mail letter was not the same pen used in the ransom note.

So you want to go ahead and Lawson out Lawson has been eliminated.

Not really.

He's fine, but good.

I always like to Lawson so I knew he wasn't the magic teakettle thief.

All right, so but now this leaves us with two potential suspects.

We still have Lydda and we have Andrew.

What's another experiment that you think we can do?

I think we need to do the fingerprints and do the magic teakettle justice.

I agree.

Let's see if we can collect some fingerprints.

OK, so the last experiment that we going to do is called iodine fuming.

And this is a technique that scientists use to look for fingerprints that's been left behind on different evidence.

And so you can collect fingerprints a couple of different ways.

If you watch some FBI shows a lot of things they do what's called dusting, but to collect a print like that, the print would have to be left on like a solid non-porous surface.

But in our case, these fan mail letters.

This is where we are looking for the fingerprints.

So we are going to use iodine fuming and iodine is a pretty toxic chemical into the way that we have this set up as we're working under a fumes hood.

So the fumes will will go up this fume hood and we will also wear safety glasses.

Right?

Safety check.

Perfect.

And so the way that we are going to do this is I have already added our iodine solution into these three containers.

And I used a plastic pipette to do that.

And so we have, as a reminder, are suspects that are remaining Andrew and Lydda And so we are going to see if we can discover fingerprints on these two fan mail letters and if they match a fingerprint on our ransom note.

All right, OK.

So the way that this will work is I'm going to open this container and then Anderson, can you place this right on top?

Perfect.

We'll do the same one over here.

It's a perfect.

All right, so now that we have our experiment set up, we have placed the ransom note in the fan mail letters on this jar and inside the jar, we had that iodine solution and that iodine solution is going to give off vapors and those vapors are going to stick to the natural oils and body fats are left behind and fingerprints.

And so before we couldn't see anything on the letter because those prints are what they call latent or invisible.

But once, after about five minutes, the clear prints that we couldn't see before will turn a kind of like an orange or brown color, and we'll be able to compare.

Yeah, yeah.

OK, so it has been about five minutes.

And so what I'm going to do is I'm going to take this off.

See all these back.

Perfect, perfect.

All right, and so, Anderson, let's see if we can quickly compare.

Oh yeah, you can definitely see some fingerprints.

You see some ridges and some loops and whirls.

I think we need to send this off to our analysts and have him take a look what I think.

Yeah, definitely.

OK, let's do that.

All right.

So our analyst has been working on these fingerprints and at first glance, what do you think, Anderson?

Well, it's not really that clear.

Lyda definitely looks like she has a whirl but I mean, still not too sure.

Yeah.

And fingerprint analysis is a little bit subjective, and there's a lot that goes into it.

You can't just say, Well, Andrew has a loop, and so does the ransom note.

And so it must be Andrew.

So how about we send off some DNA samples to our friend Neal and Sophia in Huntsville and let them take a look?

That sounds like a good plan.

All right.

So the way that this is going to work is I have some sample swabs and make sure you don't touch the end of the tip.

You're going to swab the soda can that was left behind.

We're going to stick it in this bag.

There you go.

Yeah.

Perfect.

Very professional.

And now if you could swab the envelope Lydda's envelope, the inside, yeah, just kind of where she probably licked the envelope.

OK.

Thank you, assistance.

You're welcome.

And then the last one is the Andrew envelope.

Well.

With the lab coat just feels extra special.

Right.

And so now we have all of our samples and we are ready to ship it off Neil and Sophia Good luck.

Hi, I'm Neal and Sophia and I are here at the Hudson Alpha Institute for Biotechnology in Huntsville, Alabama.

Sophia, I am sure you have heard the devastating news about the Magic Tea Kettle Kettle napping.

Yes, I've heard all about it.

I cried.

I was just crushed.

I can't imagine that someone would take that.

Exactly.

It's horrible of them.

So Anderson and Katherine have actually sent us some evidence that they would like us to run genetic forensics on.

We get to be detectives.

We are going to be genetic detectives.

But before we come to the evidence, let's talk a little bit about what genetic forensics actually tells us.

So on your right is a model of an animal cell.

It's just a standard cell.

You can see all the different parts of it.

There's a lot going on inside the cell.

Where would we find the DNA?

The DNA would be in the nucleus or right around here.

That's right, it looks like threads in this image.

And you and I, if we were to look at those threads, there'd be 3 billion little pieces all strung together in this DNA double helix.

So 3 billion of these kind of rungs on the ladder, 3 billion that we would get from mom and another 3 billion that we would get from that.

So 6 billion bits of information.

Wow.

You and I, if we were to compare our DNA, how similar do you think we would be?

Well, let's say you have you.

And then there's me.

You have blue eyes.

I have brown eyes, you have blond hair, I have brown hair.

So I'd say maybe ten, 20% similar.

So identity identity between us about ten to 20%.

Yes.

Actually, we're more like 99.1% identical What?

Yes, our DNA recipe is almost exact between us.

Yes, you and I have different eye color and hair color, but those are controlled by a small part of the DNA recipes we are.

But you and I both have two eyes and a nose, and we have the same body shape and structure.

So our genetics are so much more similar than it is different.

But we can use those tiny bits of differences to our advantage in forensics and trying to identify samples.

Here's just a little bit of DNA.

I mean, a tiny, tiny piece.

We're not going to worry so much about what the actual colored rung stand for.

But I want you to notice that if we start at this end, white, black, green, black, white, black, green, black.

So it's a repeat.

It's a four letter repeat.

And how many repeats do we have on this one to two?

Let's now look at this one here white, black, green black one white black green black two white black green black three white black green black four.

That's right.

So these differ in their repeat numbers.

Forensic genetics looks at these specific places where there are differences from person to person and then tries to measure that.

The difference is it's a way to visualize where those differences are to tell which samples potentially match which individuals.

There are four key steps that we're going to go through from the evidence all the way to the genetics.

Let's talk about those real quick, OK?

So the first step is actually sampling the evidence.

And Anderson and Katherine have already done that.

They gathered swabs from a soda can that was left at the scene of the crime.

And from a couple of envelopes.

And their hope is that that can and envelopes.

The saliva contains a little bit of cells from the individual that left that behind.

So our first task is going to be to extract the DNA from those swabs and from those samples.

Then we're going to target just a small piece of all of our genome places where there are known differences.

And we're going to make many, many copies of them so that we can visualize them.

Then we need a way to actually be able to tell the difference.

So before we talk about this, just looking at these two different sets two repeats four repeats, what can you tell about the difference?

This one is definitely longer.

That's right, it's a much bigger piece.

We're going to use that difference in size to help us distinguish the different fragments.

And we're going to use something called gel electrophoresis to make that visible.

OK, so we're going to start with the evidence.

We'll get the evidence prepped and ready.

We'll clear this space and then you and I will science it up.

Awesome.

All right, Sophia.

We are now labed up.

We're ready to go.

Our first two steps are to extract DNA from the swabs and then to amplify to make copies of the DNA using a tool called PCR.

So these are the cotton swabs that Katherine and Anderson have collected.

one from the soda can one from the envelope from Lydda and one from the envelope from Andrew going ahead and take each of those swabs and put each swab in one of these vials.

In this vial are the buffer, the chemicals that we need to extract the DNA that will break open the cell, that will pull out the DNA, and then it'll separate out everything that we don't want.

So this step gets us the DNA that we need.

This is the same tool that is used in forensics around the world.

If you have a crime scene and you're trying to identify DNA that was left behind by a sample, you would go through this forensics.

But it's also really similar to the kind of technology you might do if you were looking, for example, at an infectious disease, if you were extracting the genetic material from a virus and then making copies of it so that you could analyze it just like COVID.

So there's our initial extraction process.

Now, the next thing that we would do is that we need to make copies of the specific DNA and we're going to use those tiny tubes.

These are so small.

Yeah, these are micro centrifuge tubes.

You have to use a lot of really precise working with really small volumes when you're doing a lot of forensics.

The technology that we're going to use is called polymerase chain reaction PCR.

It's like a molecular copy machine.

Say that you had a library of books and you needed to find three specific pages in one book and make copies for 100 people.

PCR would be a lot of work.

PCR is the equivalent of going into that library, finding that book, finding those three pages and making hundreds of copies of just those three pages.

It's a chemical reaction that mimics how your cells copy their DNA right before they get ready to divide because polymerase is the enzyme.

That's exactly right.

Polymerase is the enzyme DNA polymerase that makes a copy.

So we're going to be working with enzymes, which is why we have to keep everything on ice.

We're also wearing gloves and lab coats and goggles because we want to be careful that we aren't contaminating these samples with our own DNA.

So we're being very cautious only to keep this DNA that's on the samples in the solution.

So we weren't the criminals.

We are not.

That's right.

Not us.

We did not take that magic teakettle.

We did not.

So at this point, you can go ahead and put these tubes into this machine.

This is called a thermal cycler, and the thermal cycler does that equivalent of the copying.

It's the molecular copy machine.

Go ahead and close it up.

All right.

And at this point, the copying process would start once that copying is over and it takes anywhere from 30 minutes to an hour, depending on the technology.

Then we can take the samples and move on to the last step, which is how we visualize.

OK, Sofia, we're at our last step.

We've extracted the DNA.

We've made copies of it with the PCR machine.

And now we're ready to separate out the fragments by size.

Using something called gel electrophoresis and electrophoresis works by what's in this box is an electrophoresis gel.

It's kind of like Jell-o lab based Jell-O.

You can't eat it, though you.

I would not recommend that So let's not eat the science.

But the DNA pieces can move their way through the Jell-O and the speed that they move through.

The Jell-O is based on their size, so smaller fragments move more quickly.

Larger fragments get caught and take a little bit longer to move.

OK, so we've got our samples here and we'll load them in the gel and we're going to use what's called a micro pipette.

Or this is probably one of the most important piece of equipment in molecular biology because it works with tiny, tiny volumes of liquid.

So we'll actually transfer our liquid from our micro fuge tubes into the gel, and then we'll turn the power on and we'll let it run and then we'll get our answers Sophia we've run the sample now we can take a look.

Remember, we see lots of different bands here, and each one of those bands corresponds to a different size of that DNA fragment.

The smaller size like that to repeat runs fastest and is further this direction.

The larger size.

The other direction.

So if we take a look at this with the soda, can we see two banding patterns We see the large band and then we see that shorter band.

We see a very different pattern, a different size pattern with Lydda's a sample.

So that tells us that Lydda is not the individual.

The sample for Lydda is not the same sample from the soda can.

So we can rule out Lyda from this.

Andrew, though, has that upper band and that lower band and is a pretty good.

Match.

It looks very similar to the soda can one.

Yes.

So we can rule out Lydda, but does that mean that Andrew the culprit?

We can't say just based on one marker that Andrew was the culprit.

We would want to look at multiple different markers.

In fact, in the forensics database, they look at 15 different markers.

But then they can say if there's a match at all 15, that it's very, very likely that this is the individual who matches this sample.

So we would need to do some more digging.

But at least based on this one, there's a high possibility that Andrew is the person that left the sample on the soda can win.

The teakettle was taken.

Andrew.

Thanks for watching.

Alabama STEM explorers.

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Alabama STEM Explorers is made possible by the generous support of Hudson Alpha Institute for Biotechnology, translating the power of genomics into real world results.

Southern Research Solving the world's hardest problems The Holle Family Foundation established to honor the legacy of Brigadier General Everett Holly and his parents, Evelyn and Fred Holley, champions of servant leadership Alabama works a network of interconnected providers connecting business and industr needs to a highly skilled and trained workforce.

Alabama STEM Council dedicated to improving STEM education, career awareness and workforce development across Alabama.

Alabama Mathematics, Science, Technolog and Engineering Coalition for Education advocating for exceptional STEM education in Alabama.

Alabama Math, Science and Technology Initiative, the Alabama Department of Education's initiative to improve math and science teaching statewide.