What is CRISPR?

A brief introduction to CRISPR genome editing technology, uses, and ethics from Jennifer Doudna and IGI experts

CRISPR 101

We can edit our DNA, but let’s do it wisely. In her TED Talk, IGI founder Jennifer Doudna gives a great introduction to how the CRISPR-Cas9 system lets scientists rewrite DNA sequences in any cell. She explains that this revolutionary genetic engineering tool has granted a monumental opportunity to cure genetic disease and simultaneously forces us to grapple with difficult moral dilemmas.

"...all of us [have] a huge responsibility, to consider carefully both the unintended consequences as well as the intended impacts of a scientific breakthrough."

How Does CRISPR Genome Editing Work?

Illustration showing the basics of CRISPR

DNA is the instruction manual for life on Earth. It encodes the fundamental properties of an organism — how it lives, grows, and reproduces. Changing a DNA sequence in a living cell is known as genome editing or gene editing. For a long time, this was either impossible or extremely challenging.

The discovery of CRISPR genome editing has made this process much easier. In 2012, research by IGI founder Jennifer Doudna, Emmanuelle Charpentier, and their teams developed a method of repurposing a bacterial immune system called CRISPR — an acronym that stands for Clustered Regularly Interspaced Short Palindromic Repeats — to make breaks in DNA at precise locations, using a CRISPR-associated enzyme (the Cas9 protein) like molecular scissors to cut DNA. Scientists can now edit the genome of living organisms by adding new fragments of DNA for the cell to use as a template when it repairs the break in the DNA. In this way, scientists can replace a disease-causing mutation with a healthy sequence or make other modifications to the genome.

Alternatively, scientists can use this method to “knock out” a gene entirely — a technique that is frequently used to study the functions of genes — or to modify portions of the genome that affect how genes are expressed, known as "epigenetic editing." Together, these methods give scientists powerful new tools to treat disease, improve agriculture, and study fundamental questions of biology.

Learn more:

Learn about DNA, genes, and gene editing with helpful illustrations in CRISPR Made Simple
Find out more about the history of CRISPR as a genome editing tool

Radiolab Explains CRISPR

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In this 2015 WNYC Radiolab episode, with an added update from 2017, Jad and Robert explore the world of CRISPR with Jennifer Doudna, Eugene V. Koonin, Beth Shapiro, and Carl Zimmer.

"Hidden inside some of the world’s smallest organisms is one of the most powerful tools scientists have ever stumbled across. It's a defense system that has existed in bacteria for millions of years and it may some day let us change the course of human evolution."

More Audio

Watch Cas9 in Action

Dive Deeper

Read the Book

A Crack in Creation takes the reader on a scientific journey, vividly exploring an unexpected discovery that has reshaped the future of humanity.

IGI Executive Director Jennifer Doudna wrote this popular science book about her personal and professional experiences in CRISPR research. Co-authored with her former graduate student, Sam Sternberg, A Crack in Creation offers a behind-the-scenes look at the development of CRISPR genome editing technology, its applications, and ethical implications.

Watch the Documentary

Film poster for Human Nature documentary

The CRISPR story is filled with unexpected discoveries, eclectic characters, and provocative questions.

From executive producer Dan Rather and director Adam Bolt, Human Nature breaks down the science behind CRISPR, equipping and encouraging viewers to think about the potential implications of one of history's most transformative innovations.

Visit the film's website for information on how to watch and for accompanying educational resources.