- We're testing for tilapia, right?
And you should have about the same volume
in everything, right?
I think the impact of having my students do citizen science
and investigations that are connected
to the real world, the knowledge sticks.
There's something that relates to them.
They learn that knowledge is bigger
than just academic classes.
(equipment clicks)
- [Female Student] So just click Run Test now?
- [Sheri] Yep, and now just leave it.
- So the string theory model
of education is a discovery process
for kids to be exposed to both the arts and the sciences.
The students interact with artists in residence,
scientists in residence, and entrepreneurs in residence
to give them real world experiences
they wouldn't receive elsewhere.
- In STEM, we do a lot of things
that connect with the real world.
This year, we started to do DNA and PCR,
which is polymerase chain reaction.
We bought fish from local restaurants.
- And we were just testing whether or not
the restaurants are actually serving us
what they are saying they're serving us.
- Last week, we picked eight
different restaurants that you guys go to,
many of them are in south Philadelphia.
And over the weekend we picked up samples
of white tuna and red snapper.
So this is a unit about our food
and what might be in our food
or how our food is produced.
Overfishing and replacement of different types of fish
in seafood is becoming a very big problem.
- Tuna is commonly replaced with escolar,
red snapper is commonly replaced with tilapia.
And people don't know about that.
- Some people can have a very adverse reaction to escolar.
So that's why it's a little bit problematic.
The idea is to apply a lot
of the molecular biology techniques that we learned
to their own environment.
We're gonna use the Biomeme devices.
We have a partnership
with a start-up
technology company called Biomeme.
They have a very mobile device
that they use for a lot of field work and citizen science.
- It's a portable thermocycler
that allows you to test DNA wherever you are.
So you don't have to be a scientist
to test the environment.
The person with the swab is going to gently touch
the clean cut surface of the fish.
You're going to stick it into the tube
and you're going to twirl it around a bunch.
This is the most crucial part
to make sure that you get enough DNA.
Now, hold up your strip of tubes.
We're gonna take 10 microliters
of the DNA you just extracted and put it in the middle well.
- We want to make sure that students understand
that you need to control your experiments.
So they have a positive control,
we have escolar DNA that they put in there.
Their middle one is their sample,
and then the one on the right is water.
- Once you've pipetted it into that last well,
our samples are gonna sit in here.
- The Biomeme device pulls the DNA from each sample.
You can hook up your phone to it
and there's an app where you can run it in half an hour
for the test results to come back.
- DNA is double stranded.
Through the process, we heat it up,
and it splits apart into two even strands.
So we have the base pairs of one strand,
and the we test it with one strand of the escolar DNA,
and if it matches together to make two whole strands,
it's positive for escolar.
- So our positive control is positive, which is good.
So now here's our test.
What do you think?
You tested positive for what?
- [Female Student] Escolar. - [Other Students] Escolar.
- [Sheri] Escolar, okay.
- [Dominque] So overall, over 50% of our tests
came back positive for mislabeling.
That corresponds with a bunch of articles
that we've been reading up on.
Other people have been doing the same experiment,
and they're getting the same result.
- So is that what you guys expected?
- No.
I thought they just wouldn't switch that much.
- [Sheri] It's a pretty big number, right?
- Say I was allergic to tilapia and then they replaced it,
and I thought I was buying red snapper.
Can I sue them for that?
- They might not know, and they're skating--
- Maybe they're getting fooled
by the people-- - Yeah, they're getting fooled
rather than us. - Who're giving them the fish.
- Because these were restaurants that they go to
or they have some sort of personal connection
to the people that work there,
I think that brings this extra piece
into figuring out what to do with data
to be ethical and thoughtful and have empathy.
- I wouldn't want to ruin the business,
I would wanna inform them.
But if they know about that, that's a problem.
- That does matter, what we did today.
People have the right to know what they're actually eating.
- I think that is pretty interesting that kids
in a classroom are able to find out such great information.
We could do something that could change
how restaurants produce their food,
where they get their food from and label everything.
- You can design different primers
and investigate beef patties
or identify genetically modified organisms.
The whole idea about citizen science
that you can actually do your own investigations.
They understand the value of what we're doing,
that it's not just in the classroom,
it applies beyond the classroom.
- Great, yes that looks excellent.