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If only
there was a good way to
use genomics to find a good use for all these strawberries.
Are you thinking what I'm thinking?
[inaudible]
Luckily you only need household items to do that. Otherwise, it
would take us forever to set up but let's get going.
[ Background Sounds ]
Okay, well it's super convenient. You had a craving
for strawberries. They're really easily to extract DNA from.
We'll be experts in strawberry and DNA.
Do you know how many copies of the genome that each strawberry
cell has?
No, how many?
Eight.
Eight?
Eight, 4 times more per cell than humans, so purifying DNA
from a strawberry is really easy because it has so much
DNA in it.
Oh, that's a lot.
Yeah.
Awesome.
It's sure awesome, no time to waste, let's use some science.
So let's just make sure we have all the materials we need.
Yeah, you know, it's always good to get organized.
Agreed. So first, 1 resealable plastic bag.
So I tend to use the small ones,
you can use the big ones, but small ones work really well.
You're the experts so I will listen to that.
Okay.
Two strawberries.
Very important.
Two. And if I remember right, it's actually very good to take
off the green stems and get rid of those.
Correct.
Okay.
And you can use fresh or frozen. Two teaspoons of dish detergent.
So we have the dish detergent, put that aside.
Okay.
And we have a teaspoon for measuring it.
Perfect. Alright, 1 teaspoon of salt.
So here's a teaspoon for measuring and here is the salt.
Great. Okay, a half cup of water.
So here we have a measuring cup,
[inaudible] half a cup of water. I'll just sit that here.
Perfect. Okay, 2 plastic cups.
Got those.
Got those right here.
Okay.
One coffee filter.
[inaudible] we actually have an extra but yes I have a
coffee filter.
You never know.
Yeah.
Might need 2. Half cup of rubbing alcohol,
we've got that right here.
Yep.
Got to be careful with that. One coffee stirrer.
And I got 2 just in case we need an extra.
Wonderful.
There you go.
And probably most importantly, 1 scientist or in our case, 2
scientists.
Alright.
Yes.
Okay, so you take the strawberries and what you have
to do is to basically break up the strawberries first because
then in the next step we're going to break open the cells
that are in the strawberries to release the DNA. But to sort of
help that process along, you really got to unfortunately be a
little mean to your strawberries, so you put them in
the plastic bag and you seal up the plastic bag and then you're
going to gently just want to start smashing those
strawberries and as best you can. Now there's lots of
techniques that can be used for this. You don't want to get too
violent because if you do, you could spray strawberries all
over your kitchen table or all over yourself. But at the same
time, you have to really work it good as much to get sort of
strawberry puree. We just keep getting this to the point that
all the big pieces are broken up and in doing so, you will then
have it to a point where you can then go to the next step where
you're going to break open then individual cells in strawberries
and let the DNA come floating into solution. Here's the thing,
in this bag are smashed up strawberries with a bunch of
individual cells in them. And maybe one way to think about is
like a water balloon and that's the cell and what we need to do
is to break open that water balloon so that the DNA will
come floating out. Now like a
water balloon like you might use a nail to pop it but for this,
what you do if you're dealing with a cell, is you use a
detergent like detergent you use for--
[inaudible].
[inaudible] so we're going to make a solution that's going to
both have detergent in it but it's also going to have other
things like salt and water that make the DNA happy and
comfortable floating around inside of a cell.
[inaudible].
[inaudible] take this what we call an extraction liquid, okay?
Little concoction sounds [inaudible].
[inaudible] start you at 2 teaspoons of the detergent.
Okay, sounds great. You want some?
No, no I already had breakfast.
Okay, just want to check, looks good though.
Okay, 2 of those, 1 teaspoon of salt.
Yeah, maybe you can use a different teaspoon.
Yes, good thing I have 2.
Yep.
Alright. Perfect.
And then remember we have that half a cup of water--
Yes.
that was poured to the very top.
I'm going to meet you halfway.
Alright, thank you very much and then I'll just pour it in using
my skills as a scientist and there you go. And now just
shake it up a little.
[inaudible] shake.
Yeah, yeah and all you're really wanting to make sure to do is to
make sure the salt gets into solution and that detergent sort
of gets evenly dispersed [inaudible].
Okay.
Okay, so that's our extraction liquid.
Cool.
So now we're basically going to use that detergent like a little
pin to pop the water balloons. Use the detergent to break open
those strawberry cells. [inaudible] open this up.
Let's do it.
You can just pour it in.
Okay.
And there we have it. And so now you seal it. Now here you can't
smash, you don't even want to smash because, of course, if you
really start smashing then you really spew out the liquid and
that would [inaudible] and
actually the other thing is you don't want to be too tough with
this because otherwise you'll get a lot of bubbles. But you
just want to sort of work this around just like you're making a
smoothie by hand. And so but here's the thing is that while
all the DNA is now collecting in the liquid, if you look in
there, you have a lot of other stuff that's in the way. Now
scientifically, we might refer to that as cellular debris but
you know it's just you know strawberry schmutz and you got
to get rid of that strawberry schmutz and so that's why we use
a coffee filter. It's now time to get rid of this schmutz and
get the liquid that'll contain the strawberry DNA, so
[inaudible] you can fold that for me.
[inaudible].
I'm going to use this as a filter. Now you can use a coffee
filter, sometimes you could use gauze if you happen to have some
gauze in your house. You just do whatever it takes to filter out
all that schmutzy stuff that was in the strawberries and just let
things slowly leak through, seep through like you're making drip
coffee. So when most of the liquid has filtered through,
what's good is to just remove that filter that contains all
that strawberry schmutz and we can just put it on the side, we
don't need that anymore.
Alright.
So this is basically the extraction liquid, which has the
insides of all the cells of those strawberries including the
DNA. And in order to get the DNA to come out of solution, we do a
scientific step which is called precipitation--
[inaudible].
which is basically a way of getting a compound or molecule
to sort of come out from being in the liquid state to being in
a solid state. To do that, we use this rubbing alcohol--
Alright.
which you often want to have it be a little bit cold and I know
this was in the refrigerator and that's good. You just want to
add a equal amount, so what I always do is I just sort of
estimate where my finger is as sort of the equal amount and you
can just pour the alcohol up until about that amount--
Okay.
and a little more [inaudible] that's good.
Okay.
[inaudible] like that. And then what you want to do is not be
overly harsh with this but you can sort of see there's almost
like a layer, the alcohol's a bit on top--
[inaudible].
the extraction liquid's on the bottom, [inaudible] just sort of
roughly sort of gently swirl it around and what you start to see
forming sort of between those 2 layers is like a flocculent-like
material sort of almost looks like cotton.
Yeah.
And as you swirl more and more and it gets more and more mixed
you'll see more of it forming and that flocculent material is
the DNA.
That's awesome.
But you know it's very whitish and it's sort of very viscous
and what does it really look like in real life?
It kind of looks like snot.
It does look like snot and so-- And when you start to see big
things of snot then you know it's really working well and you
can even see here as we've done this, you can really start to
see some of this precipitated DNA forming.
Wow, look at that.
And we can get more in a bit but what you can do is when you
start to see it, that's where the coffee stirrer comes in and
you can just sort of fish that out. Look at that, look at that.
That's awesome.
That is strawberry DNA, which, again, to our eyes
looks like a bunch of snot.
[inaudible].
But in fact if we could look at it at a molecular level, it
would just consist of that classical double helix, that
sort of the iconic view of DNA
but this is strawberry-- Purified strawberry DNA
[inaudible] you could get and you could if you wanted to keep
swirling but you can see you've got a tremendous amount there--
[inaudible].
which is great. And just imagine, you did all of this
using materials that you have in your kitchen, so you can do
science in your kitchen and do something that is as wonderful
as isolate DNA from a strawberry.
That is really cool.
DNA
extraction.
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Science is delicious.
Especially the DNA.
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