(bright electronic music) [Mr.

C.]

What time is it?

[All] It's "Science Time"!

♪ Yo, it's science, science, science time ♪ ♪ Let's all stop and just unwind ♪ ♪ One, two, three, four ♪ ♪ Here we go ♪ ♪ Learn so much your brain explodes ♪ ♪ Lessons so cool, so fresh ♪ ♪ Beats so big, you'll lose your breath ♪ ♪ Learning facts and real cool stuff ♪ ♪ Scream for more, can't get enough ♪ ♪ It's, it's science time ♪ ♪ It's fun, you best believe ♪ ♪ Explore and learn new things ♪ ♪ Come and join me please ♪ I'm Mr.

C., and this super smart group is my science crew.

Working together with my crew makes learning so much fun!

Actually, you should join us.

Let's give science a try with a simple DIY.

Today, we're talking about forensics.

What time is it?

[All] It's "Science Time"!

Welcome back to "DIY Science Time".

My name's Mr.

C., and I'm so glad that you're here to be part of our science crew today.

(whip cracks) Today, we're talking about cookies!

That's right, cookies.

And I made a special batch of cookies right here, and they are delish, whoa!

Wait a minute!

My cookies are missing.

This is not good.

I wonder- No, don't touch the glass, Mr.

C. That's evidence!

You're right, Linky.

I shouldn't touch this, because this is evidence.

This is now a crime scene.

A cookie crime scene!

A cookie crime scene.

And the one thing I take more serious than science are my cookies.

That's right.

This is a problem, and I am gonna have you gather some materials, because instead of an episode on cookies, we're talking forensics, right here, right now.

And I have some really good friends at the CBI, the Cookie Bureau of Investigation.

I mean the FBI.

And they're gonna help us come to a conclusion about who messed with me and my cookie jar.

Oh no!

Not the cookies!

Let's gather some evidence and materials to help Mr.

C. determine who the cookie bandit is.

For this activity, we'll need paper, a pencil, tape, cocoa, baby powder, and don't forget your super sleuthing science notebook.

A science notebook is a tool that every scientist should have because it gives us a place to record all of our learning.

Taking notes and being organized allows us to be better scientists.

A science notebook allows us to go back and review all of the data and information we've gathered during our experiments.

Plus, it allows us to share results with other scientists who might be interested in learning more about what we discovered.

Whenever you see the notebook pop up on the screen, like this, it's a reminder that this is a good place for us to jot down new information during the show.

I've already added a title and a list of materials for today's activity, but our crew is still going to have lots of information to collect and organize as we go through our experiments.

Most importantly, the more you use a science notebook, the better you'll get at taking notes and recording data.

If you don't have a science notebook already, download a copy of Mr.

C.

's science notebook from the website.

Forensic science is any science used in the court of law.

Forensics applies science principles and methods to investigate things like dentistry, accidents, and injuries.

Forensics often uses DNA analysis and fingerprint analysis to help make decisions, and often takes place in a lab.

Every person has a unique fingerprint that can be connected to them and only them.

Fingerprints can be in the shape of an arch, loop, or a whorl.

Every time you touch something, you are leaving your fingerprint on a surface.

What's even more interesting is the fingerprint you left on the piece of glass also left something very specific to you that is a unique identifier.

Your skin, sweat, and oil contain DNA.

DNA, or deoxyribonucleic acid, is the fundamental molecule that carries all of the genetic instructions of all known organisms.

It is the blueprint for life!

DNA is a double helix, or twisted ladder, and is made of four chemical bases.

Adenine, guanine, thymine, and cytosine.

Think of DNA as a massive library of instruction manuals, the genes, for building and running a person.

The letters in the code form words, or codons, that cells read to make proteins for the body.

DNA is responsible for giving you your hair color, your eye color, height, and even physical talents.

-Field trip time!

-(air horn blowing) I am very thrilled to say we're at the TIDE Center Research Laboratory with Dr.

Matt Sherill, and Melissa Clinard, and today, we're going to be talking forensics, sort of, and understanding the idea of how chemicals work to present themselves so we can identify really cool stuff.

I am so excited to be here today.

This is awesome.

Yeah, we're very glad to have you.

Welcome to the TIDE Center.

So I see a couple things happening.

I see some solutions.

So what we have here is we have three different solutions, so there's different chemicals that are dissolved into this water, in this case, as our solvent.

Melissa is going to mix these together and what we'll see is how the chemicals change over time.

The indicators that are present in the solution will pick up those chemical species changes, and give us different colors.

When she mixes them together, what we have in there is iodine, and the iodine will go through different chemical states, which will take on different colors.

So right now, it's clear, but when you mix it together, it'll turn yellow, and then blue, and then the reagents that we have in there will start that cycle over, and it will continually flash, as the different state of iodine become most present, or more concentrated in the solution.

So as this reaction is going on, one of the things it produces is the oxygen gas.

So you'll see the rate of oxygen production begins to pick up, and then here in just a couple of seconds, we should see it flash blue.

There it goes.

Oh, that's so cool.

So basically, when it goes back to clear, that's essentially the starting condition that we had.

The chemicals then continue to eat on that, and it goes back to clear, and then yellow, and blue.

So out in the field, we also have some indicator kits, where you can take samples from evidence, or whatever you happen to be investigating, put some indicators on there, and depending on the color changes that happen, that will tell you what those chemicals were.

That's so cool.

Yeah, it's amazing.

The science of forensics.

That's so interesting.

And it looks like maybe it stopped.

Yeah, so it looks like we've reached the end of it, so now you're at that dark blue, almost black species, and that's where it will stay.

That is absolutely amazing.

So what is that yellow thing?

This is actually a large scale reactor.

This is a five liter.

We use it to scale up our chemical reaction.

We can actually turn it on if you wanna see.

Yeah, that'd be great.

It's got a central stir shaft, and you've got your liquid in there, so that's where the chemical reaction would be taking place, just like it was in the beaker, but this allows us to make more at one time.

It's really interesting to see this chemical reaction taking place, the tools and equipment that you have, it's been fantastic.

Thank you so much for taking the time and hanging out with me.

You're very welcome.

Thank you for coming, and we would love to have you back.

Oh, I would definitely love to come back.

Thanks, everybody!

I know I put the cookies in here the other day preparing for the show.

-(tense music) -(counter beeping) Let's seal it up so I stay out of these.

Perfect.

Set them over here.

Cover it up.

And now we set and forget.

Yeah, that's exactly how that happened.

And to think about it, our suspect list has to be the science crew, because they're the only ones who have access to the lab after things get locked up.

And that brings me to what Dr.

Sherill said.

He mentioned that he works backwards from a solution to identify what's inside.

And we can sort of do the same.

My chocolate chip cookie recipe uses dark chocolate, and I know for a fact that Penelope doesn't like dark chocolate.

So we can rule her out as a suspect, and now we can figure out who the culprit still is.

The world population is over eight billion people, but did you know that no two people have the same set of fingerprints?

That seems impossible, right?

Even identical twins with DNA that is almost exactly the same have their own unique fingerprints.

This is because fingerprints aren't only influenced by our genes.

While in the womb, things like pressure, blood flow, and the way fingers touch their surroundings make the ridges grow in ways that are unique to each baby.

We are going to extract the code of life from these strawberries.

First, you're gonna need a third cup of water, a half a teaspoon of salt.

Grab a tablespoon and add your dish soap, and we're gonna stir it up.

Now this is gonna be our extraction fluid.

This is what's going to break down the cells in the strawberry so that we can pull out that DNA.

Grab yourself a baggie, and now you're going to put in about a golf-sized ball worth of strawberries.

Get as much of the air out as you can.

And then you're gonna start smushing.

Try to get out as many of the clumps as you possibly can.

So I think we're pretty good.

You want it nice and smooth.

I got most of the chunks out.

And now we add three tablespoons of DNA extraction fluid.

We're gonna lay this down.

I'm gonna try to get as much of the air out as I can.

And now I'm going to gently push it without creating bubbles.

I don't want to create bubbles in here, but what we're doing is we're trying to break down the cells so that the DNA can be extracted.

Making biscuits.

All right, we've been mixing it for about a minute, and now we're going to strain all the strawberry chunks from the liquid.

I'll tighten the cheesecloth to force the liquid out.

And now eliminate some of the foam by pouring into a new cup so we can extract the DNA in the next step.

You're going to need some ice cold isopropyl alcohol.

I'm using 91%.

This has been in my freezer for an hour or so.

It's super cold.

Measure a quarter cup.

And then carefully pour.

We want to minimize the mixing with the strawberry mush.

Now we're gonna let this sit.

And I can already see the DNA precipitating, which means it is coming together in the rubbing alcohol.

That's strawberry DNA.

Now grab your skewer stick, and you're going to put it in here, and you're going to just swirl it around and pick it up.

And that, ladies and gentlemen, is strawberry DNA.

That is the code of life for strawberries.

I have DNA, you have DNA, and it makes me wonder, what other fruits could you extract DNA from?

Did you know that koalas have fingerprints just like humans do?

The swirls and patterns are so similar that you might have a hard time telling them apart from human ones.

Although koalas and humans aren't closely related on the tree of life, they both have evolved this similar trait completely on their own.

There are claims that koala fingerprints could confuse crime scene investigators because of their similarities.

However, no cases of this type of mix-up have ever been documented.

The science of forensics is so precise and advanced that it likely would be very easy for experts to tell koala and human fingerprints apart.

You might even say these super smart forensic scientists have the right koala-fications -to solve their cases.

-(drum beat kicks) -Field trip time!

-(air horn blowing) I am super excited, because I am at TEDAC, and I'm here with Kim, who is a forensic examiner, and she's going to help us understand how we can take information that's here on this table, which is our evidence, and figure out a possible crime?

Is that what I'm understanding?

Indeed.

Welcome to the FBI lab.

Thank you, I'm so excited to be here with you.

Thank you for having us.

You're very welcome.

So I work in the trace evidence unit, and one of the things that we do is examine fabrics that are found at crimes.

So today, we're looking at a case where we have six pieces of fabric, all the same crime, but came from three different locations.

So we're actually gonna see if we can physically match these back together, and thus associate the crime scene to the vehicle that was abandoned, and then back to the subject's home, and that will then link these three together, and tell us that perhaps it is the subject who was at the crime scene.

So we're sort of working backwards?

Crime has happened, and now we're trying to figure out what goes where, and that's gonna tell us a story.

Yes.

Because one of the other things we have to figure out, that's gonna be a little bit more difficult because there's a pattern, is how should each of these pieces be oriented?

We have these two together, which we've now linked our crime scene and the subject's home.

And we have an edge.

So we know those two orient in that direction, but now we have these four other pieces to see if we can make them fit.

[Mr.

C.]

I think we may have a match.

[Kim] Okay, yes.

[Mr.

C.]

So I pulled that from the abandoned vehicle, over here with what we found at the home?

[Kim] Mm-hmm.

So this is very common, right?

People are going through, they're trying to find the pattern, trying to figure it out.

And it's okay to help.

Okay.

So this is good, because in these three, we have now linked all three places.

That is foundationally what we're trying to do.

So we're actually looking to make sure that the thread that runs this way, for instance, on these pieces, aligns at a microscopic level.

[Mr.

C.]

It's like a zipper.

You can see them going (makes zipping sound).

Yes.

If I sat here and tried to tear over here, you would not get exactly the same pattern.

So really, for a kid at home who's thinking about this, like the tear itself is almost like a fingerprint -for that fabric.

-Yes.

For that specific place.

That is super cool.

Could we look at maybe one of these pieces or a different piece under the actual -really heavy duty microscope?

-We can.

That sounds fantastic.

-Let's give it a try.

-Okay!

-Hey.

-Hey, how are you?

I'm doing good, how are you doing?

-You must be Annie.

-I am.

Kim sent me with a piece of fabric.

She said you're also a forensic examiner?

I am.

We have a full on microscope that we can look at it.

The colors look the same, the patterns are matching up where the flower is.

It's almost like you can see the cut snips of maybe the scissors that were used.

Every time you reposition, or take a break, you're gonna leave a different mark.

So we can zoom in on those marks.

[Mr.

C.]

Oh wow, that's so much closer.

So right here, you can see that each side has two yarns that go over and under, and over and under.

And we can look at the twist of those yarns.

We can look at the color, we can look at if there's any juts out.

And we just do that to fit the whole piece together.

That's so cool.

I appreciate your time, and we'll keep on learning.

-Have fun.

-Thanks.

No problem.

Kim gave me a great idea.

I didn't even think about the fabric as being a clue to our crime scene.

So let's take this off.

What is this?

(Mr.

C. gasps) Look at this.

It's a huge gap!

And it looks like it's been cut.

I haven't seen any fabric around the house or here in the lab, so I'm not sure how this is gonna be helpful.

I see evidence behind you.

Interesting, back?

Not that side.

No, I don't see anything back there.

Over by the typewriter.

(Mr.

C. Gasps) -I see something!

-(audience gasps) It's the fabric!

Just so I've said it, my robot hands can't cut that fabric.

-Look at this.

-(audience murmuring) Evidence.

Let's see.

It's the same fabric with the same pattern.

The pieces are fitting together perfectly.

Let's use our digital microscope just like we did at the FBI.

So we can see here that that is a perfect match.

Look at that, how it comes together.

You can see, it fits perfectly there, and you can see the threads are connecting.

It makes me wonder, how did that fabric get over there?

It means, it means our suspect has been walking around and getting into everything.

They've been all over this lab, and I bet their fingerprints, their fingerprints are probably also all over this lab!

Field trip time!

Hey, how are you today?

Hey, good.

How are you?

You must be Jill.

That's me.

You're a forensic examiner also?

Mm-hmm.

Oh, that's so cool.

So are we gonna get to do fingerprints today?

Yeah.

You're in blue, and I'm in white.

Why is that?

'Cause I need to be in blue, so we're gonna get dirty today, so you need to be in blue.

How do we make that happen?

Boom.

Whoa!

That's awesome!

So now that I look like you, like what do I need to know about fingerprints?

Yeah, so we have different types of substrates.

This would be a nonporous substrate.

Do you wanna take a look?

-Okay.

-So it's nonporous, because water can't go through it.

That means there's something that's probably porous also, right?

There is, yeah.

Here's a piece of paper.

Give me the money.

(laughs) Okay.

Is there something in between?

Yup.

That'd be semi-porous.

Something like shiny cardboard.

Shiny cardboard?

Okay, so it's shiny cardboard.

And it looks like you've taped it up so it doesn't fall apart.

Yeah.

Tape's another substrate.

The adhesive side of tape.

[Mr.

C.]

The adhesive side of tape?

Oh, that's cool.

I didn't even think about that.

Yeah.

What does it mean, substrates, why are they important?

So substrates are important because we have to process the items of evidence differently based on their properties.

So for instance, the fingerprints, the latent prints are gonna sit on top of something that is nonporous, so we have to use chemicals like superglue fuming, and dye stains to see them, or visualize them.

But for things that are porous, the latent print residue is going to soak into them, therefore we need to use different types of chemicals to soak into that residue and develop the latent prints.

-So I have to ask a question.

-Mm-hmm?

[Mr.

C.]

Did I just leave my fingerprints all over these items?

[Jill] You did.

So we're gonna be able to develop my fingerprints right now?

Exactly.

Oh, that's cool.

-Let's get to it.

-Okay.

First we're gonna make the ABP.

It stands for alternate black powder.

Two scoops should do it.

And it's just a 50-50 solution, and half of Liquinox, which is basically a detergent.

And we're looking for a cake batter consistency.

We're gonna remove the tape with tweezers.

Once we've got the tape off, I'm gonna wet the surface to help adhere the back of the tape.

Adhesive side up to the sink.

So I'm gonna use this camel hair brush, apply some ABP on it, and just directly paint onto the adhesive surface.

And then I'm gonna let it sit for 30 seconds to develop.

And rinse it off.

(Mr.

C. Gasps) Wow.

-I see a print.

-Oh, that's so cool.

[Jill] And there you go, we have a beautiful print.

[Mr.

C.]

It just came out of nowhere.

[Jill] Yeah.

Well that was so awesome, Jill.

I can't believe what we just saw.

We literally were able to take fingerprints off of paper, and then here we did the painting, and we were also able to pull prints off of cans.

So the different substrates, I never thought it was so complex to work with those substrates.

Yeah, but super simple to develop right?

We've really left our print on this part of the show.

-So.

-(Jill laughs) Thank you for spending time with me today.

I really appreciate it, and I look forward to hopefully working with you in the future again.

Yeah, great meeting you.

Thank you.

We're going to build a DNA model that uses nine base pairs, or three codons for the sequence.

You can create your own unique DNA sequence as well.

Remember, guanine and cytosine always pair, and adenine and thymine always pair.

For our sequence, we're going to do A. A. T. G. G. C. T. G. A. Now add the corresponding marshmallow to the toothpick, and push it through the licorice.

Be sure to follow the sequence that you've created.

Now place the matching or complimentary DNA base on the toothpick, and remember the base pairing rules.

A pairs with T, and G pairs with C. Match up all of your pairs, and then attach the second licorice, which represents the DNA backbone.

Now twist it to the right, and you have a DNA model.

Our model isn't exactly accurate, but it does allow us to practice connecting our base DNA pairs.

Pretty sweet science.

It's been a very busy day, with all of our experiments, and our visit to the FBI.

DNA extraction, trace evidence, and substrates, all of that is so cool.

I really loved how we were able to extract DNA from those strawberries.

And we used the digital microscope to see tears and cuts on fabric.

Most importantly, what other fruits do you think would be good for DNA extraction?

Could that help us solve this case?

If anyone can do it, Mr.

C. can.

A super easy way to pull your fingerprints is using a pencil and a graphite.

Make a square on a sheet of paper.

And now you're just going to scribble it in until it's completely filled up and super, super dark.

Once you have that, grab a piece of tape.

I'm gonna use my opposite hand, and I'm gonna put this down into the graphite, and then I'm going to place my fingerprint on it.

Ooh, that looks pretty good.

Set it down.

So I have a fingerprint.

Here's the cool thing.

We took fingerprints from the entire crew, so we have their fingerprints, and I have my fingerprint, and now we're going to try to pull fingerprints off of our cookie jar to identify the culprit.

And I'm just gonna kind of use the light here in the lab to get an idea if I can see any prints.

I can see two prints.

Now, they're not very visible yet, but you can see them with the naked eye.

I'm going to take some cocoa powder, and I'm going to place it on top of the prints.

I'm gonna dump a little bit onto it.

Or a lot of it.

(laughing) So now I'm going to just wipe this away.

Oh my gosh.

Do you see it?

We have prints.

Wipe a little bit more away.

You can actually see the print.

And what we're gonna do now is I'm gonna take another piece of tape.

Okay, I've got that.

I'm gonna lift.

Oh yeah.

It looks like we're gonna have a print -to identify the culprit.

-(audience gasps) Let's get it on our paper.

All right, so it's not very dark.

And then we have this print, and they look ... (mysterious music) Very similar?

(audience gasping) Wait.

-I- -(dreamy harp music) (cookies being crunched) It's all coming back to me.

(sighing) I should probably just try one.

-Cookies.

-(counter beeping) Few more won't hurt.

Cookies!

(counter beeping) There's only two cookies left.

Oh no.

Let's close it back up.

There we go.

Two cookies should be enough for the show.

Where'd that come from?

One more cookie won't hurt anybody.

(counter beeps) Mm.

I can't believe it was me the whole time.

We solved the case.

I solved my own case.

And it's so awesome to think we used and learned all about these forensics, and how they can be applied to cookie theft at the house.

And I just have to say that missing cookies should never be a crime.

It should just be something we enjoy because cookies are delicious.

And speaking of which.

I mean, I do have two cookies left, so I should probably just eat them and just finish this up.

So thanks to all of our friends at the FBI, thanks to all of you for helping me solve the crime, -and most importantly.

-(counter beeps) Keep learning.

Keep exploring.

Keep having fun, and remember, cookies and science is wherever you are.

Take care, everybody!

Bye!

(Mr.

C. chomps cookies) Wait, wait.

The true crime is if you don't get your "DIY Science Time" notebook.

Download it today!

♪ It's science time ♪ One, two, three.

(all chant) I just have a problem.

It's cookies.

Now grab a stew.

Stewer stick.

Wow!

♪ We made some cookies ♪ (all laughing) I love it.

(Jill laughing) Mm.

They're hitting the spot.

It looks like a booger.

I gotta quit eating them, though.