and about biology for me is that there's always more

to be discovered, and every time we feel like we've figured

something out, it seems to open up several more questions.

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Scientists have appreciated for a long time

that once we understood the DNA sequence in cells,

if we had a tool that would allow easy manipulation

of that sequence, that that would be

a very powerful kind of technology.

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CRISPR is a technology for changing the sequence

of DNA in cells in a precise fashion to correct mutations

that might otherwise cause disease.

It's going to enable a lot of science to be done

that was impossible to do in the past.

So the way the CRISPR technology works is

by the action of a protein called Cas9 that functions

like a molecular scalpel for DNA.

The CRISPR Cas9 system has an amazing ability

to recognize a particular DNA sequence in a cell that may be

malfunctioning, and then disable it by cutting the DNA.

We call this gene editing, and we can use it

to disable or repair a mutated part of the gene,

which may be causing disease.

For Cas9 to find the malfunctioning DNA,

we attach it to an RNA sequence

that matches the DNA sequence we want to edit.

Then we put this RNA Cas9 combination into the cell.

It finds the mutant DNA and uses the chemical reaction

to cut the DNA strand right at the spot

where it's malfunctioning.

After that, we can sometimes insert the correct version

of the gene for the cell to work properly again.

It's a very exciting technology that's going to do

a lot of good in human society and for human health.

It stretches from human therapeutics

to agricultural applications to thinking about

how do we make better biofuels.

These would be incredible outcomes, I think,

of using this kind of technology in the future.

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