In 2012, Doudna and her colleagues made a new discovery that reduces the time and work needed to edit genomic DNA.
Their discovery relies on a protein named Cas9 found in the Streptococcus bacterial "CRISPR" immune system that cooperates with guide RNA and works like scissors.
The protein attacks its prey, the DNA of viruses, and slices it up, preventing it from infecting the bacterium.
This system was discovered by Francisco Mojica, but she and Charpentier showed for the first time that they could use different RNAs to program it to cut and edit different DNAs.

In 2015, Doudna gave a TED Talk about the bioethics of using CRISPR.
As CRISPR becomes increasingly used to edit multicellular organisms, Doudna continues to be called upon to speak clearly about the ethics of changing an organism's function using CRISPR.
Their discovery has since been further developed by many research groups for applications ranging from fundamental cell biology, plant, and animal research to treatments for diseases including sickle cell anemia, cystic fibrosis, Huntington's disease, and HIV.
Doudna and several other leading biologists called for a worldwide moratorium on any clinical application of gene editing using CRISPR.
 Doudna supports the usage of CRISPR in somatic gene editing, gene alterations which do not get passed to the next generation, but not germline gene editing.

The CRISPR system created a new straightforward way to edit DNA and there was a rush to patent the technique.
Doudna and UC Berkeley collaborators applied for a patent and so did a group at the Broad Institute affiliated with MIT and Harvard.
Zhang at the Broad Institute had shown that CRISPR-Cas9 could edit genes in cultured human cells a few months after Doudna and Charpentier published their method.
 Before the UC Berkeley patent application was decided, a patent was granted to the Broad investigators and UC Berkeley filed a lawsuit against the decision.
 In 2017, the court decided in favor of the Broad Institute, who claimed that they had initiated the research earliest and had first applied it to human cell engineering thus supporting editing in human cells with evidence but that the UC Berkeley group had only suggested this application.
 UC Berkeley appealed on grounds that they had clearly discussed and spelled out how to do the application the Broad had pursued.
In September 2018, the appeals court decided in favor of the Broad Institute's patent.
 Meanwhile, UC Berkeley and co-applicants' patent to cover the general technique was also granted.
 To further cloud the issue, in Europe the claim of the Broad Institute, to have initiated the research first, was disallowed.
The rejection was due to a procedural flaw in the application involving a different set of personnel listed in the lawsuit and the patent application, leading to speculation that the UC Berkeley group would prevail in Europe.
 Doudna has co-founded Caribou, a company to commercialize CRISPR technology.
She is also a cofounder of Scribe Therapeutics which pioneered CasX, a more compact, next-generation Cas9 which can efficiently cut DNA.

In addition to the CRISPR breakthrough, Doudna has discovered that the hepatitis C virus utilizes an unusual strategy to synthesize viral proteins.
This work could lead to new drugs to stop infections without causing harm to the tissues of the body.
In 2012, Doudna and her colleagues made a new discovery that reduces the time and work needed to edit genomic DNA. Their discovery relies on a protein named Cas9 found in the Streptococcus bacterial "CRISPR" immune system that cooperates with guide RNA and works like scissors. The protein attacks its prey, the DNA of viruses, and slices it up, preventing it from infecting the bacterium. This system was discovered by Francisco Mojica, but she and Charpentier showed for the first time that they could use different RNAs to program it to cut and edit different DNAs. 
In 2015, Doudna gave a TED Talk about the bioethics of using CRISPR. As CRISPR becomes increasingly used to edit multicellular organisms, Doudna continues to be called upon to speak clearly about the ethics of changing an organism's function using CRISPR. Their discovery has since been further developed by many research groups for applications ranging from fundamental cell biology, plant, and animal research to treatments for diseases including sickle cell anemia, cystic fibrosis, Huntington's disease, and HIV. Doudna and several other leading biologists called for a worldwide moratorium on any clinical application of gene editing using CRISPR.  Doudna supports the usage of CRISPR in somatic gene editing, gene alterations which do not get passed to the next generation, but not germline gene editing.
The CRISPR system created a new straightforward way to edit DNA and there was a rush to patent the technique. Doudna and UC Berkeley collaborators applied for a patent and so did a group at the Broad Institute affiliated with MIT and Harvard. Zhang at the Broad Institute had shown that CRISPR-Cas9 could edit genes in cultured human cells a few months after Doudna and Charpentier published their method.  Before the UC Berkeley patent application was decided, a patent was granted to the Broad investigators and UC Berkeley filed a lawsuit against the decision.  In 2017, the court decided in favor of the Broad Institute, who claimed that they had initiated the research earliest and had first applied it to human cell engineering thus supporting editing in human cells with evidence but that the UC Berkeley group had only suggested this application.  UC Berkeley appealed on grounds that they had clearly discussed and spelled out how to do the application the Broad had pursued. In September 2018, the appeals court decided in favor of the Broad Institute's patent.  Meanwhile, UC Berkeley and co-applicants' patent to cover the general technique was also granted.  To further cloud the issue, in Europe the claim of the Broad Institute, to have initiated the research first, was disallowed. The rejection was due to a procedural flaw in the application involving a different set of personnel listed in the lawsuit and the patent application, leading to speculation that the UC Berkeley group would prevail in Europe.  Doudna has co-founded Caribou, a company to commercialize CRISPR technology. She is also a cofounder of Scribe Therapeutics which pioneered CasX, a more compact, next-generation Cas9 which can efficiently cut DNA.
In addition to the CRISPR breakthrough, Doudna has discovered that the hepatitis C virus utilizes an unusual strategy to synthesize viral proteins. This work could lead to new drugs to stop infections without causing harm to the tissues of the body.
Jennifer Doudna