>> Just a few years ago,
a new technology came out
which is allowing scientists
to make changes to DNA in cells.
It's called CRISPR, which
involves a CRISPR protein too,
that can be instructed
with a small piece of RNA
to target and cut any piece of DNA.
A gene if you will.
Quite like how we use a word processor
to edit and fix typos in a document,
you can cut out unwanted genes
and you can insert in new ones.
With this, the possibilities are endless.
Genetic diseases, cancerous mutations,
viral infections can all
be potentially cured.
But with great power comes great risks.
This protein is not always very accurate
about following instructions,
and it can make mistakes by
modifying unwanted genes,
resulting in dangerous side effects.
One of the biggest challenges
in solving this problem
is the lack of full understanding
of how this CRISPR protein works.
And what is the best way
to understand something?
By watching it in action, right?
For example, we know Roger Federer
to be one of the world's best athletes.
Why and how do we know that?
Because we can watch him play
and analyze his wonderful technique.
But watching these CRISPR protein tools
directly is impossible,
because unlike Federer they're so small
that even the most advanced microscopes
cannot capture them in real-time action.
So here's how we solved the problem.
We tagged this protein and the DNA
with very very small,
but very very bright dyes
and built a customized advanced microscope
with a powerful camera to see them.
We could get the signal
and monitor the reactivity in real-time.
Another very useful property of these dyes
is that the colors they emit
is dependent on the distance between them.
So if red and green dyes are very close,
you will see more of red.
If they are far apart you
will see more of green.
So we are now using them in pairs
to monitor real-time
changes in the protein
and the DNA at multiple locations.
For example, if Federer had been so small
that you could not directly see him,
we could put the red and
green dye pairs in his legs,
and as he plays tennis the output color
would tell us the real-time changes
in distance between his legs.
This strategy is helping us to map out
critical shape changes of this protein
and DNA during the DNA editing,
which will help us tune the
behavior of this protein
so it does not make mistakes.
Quite like how a coach can
take a super-talented kid
and turn him into Federer
by carefully analyzing his or her actions
and correcting the mistakes.
Thank you.
(audience applause)
