CRISPR is a gene-editing tool that lets scientists cut out and replace damaged DNA

Originally a bacterial defense system against viruses, CRISPR uses guide RNA and a protein called Cas9 to identify and cut specific DNA sequences. Scientists can repurpose this system to switch off faulty genes, insert new ones to treat genetic diseases, or modify organs grown in other animals so that they appear less foreign to a human immune system.

CRISPR allows scientists to cut out and replace faulty or unwanted DNA, which can help treat genetic disorders, such as sickle cell disease, and create genetically modified organisms, such as allergen-free foods.

Different enzymes can be used in the CRISPR system to modify how DNA is cut

The system uses RNA sequences to guide enzymes like Cas9 to specific spots in DNA, where they cut or modify genes. Unlike Cas9, the Cpf1 enzyme makes staggered cuts, which helps insert new DNA more cleanly.

CRISPR-Cas9 enables precise genome editing using a simple RNA-guided system

Jennifer Doudna's research uncovered how bacteria use the tool as an immune defense by cutting viral DNA. She and Emmanuelle Charpentier received the 2020 Nobel Prize in chemistry for showing how this mechanism could be engineered to target and edit genes in living cells.

A deeper (nontechnical) dive into how CRISPR works

Extra crispy? No, it's CRISPR, but this gene-editing technology is "extra" in the sense of being momentous and destined to change everything. Through CRISPR, scientist exploit a quirk in bacteria immune systems, allowing them to potentially, and quickly, control genes, remove undesirable traits, and add preferred ones. The possibilities and applications are endless.

CRISPR-Cas systems act as genetic memory banks for defending bacterial cells

When viruses called phages inject DNA into bacteria, some bacterial species store bits of this DNA in their own genomes. This allows them to recognize and destroy the same virus if it attacks again.

Explaining CRISPR at five levels of technical detail

CRISPR is a new area of biomedical science that enables gene editing and could be the key to eventually curing diseases like autism or cancer. WIRED challenges biologist Neville Sanjana to explain this concept to 5 different people; a 7-year-old, a 14-year-old, a college student, a grad student and a CRISPR expert.

Despite its potential, CRISPR still fails 15% of the time

Biochemists from UIC found that persistent Cas9 binding to double-strand breaks impacts DNA repair efficiency and the effectiveness of the gene editing tool. RNA polymerase collisions also dislodge Cas9, which affects the efficiency of the tool.

Restoring vision in impaired patients via CRISPR

Since CRISPR was revealed as a gene editing tool in 2012, it has been on an accelerated track to real-world applications. Among other clinical demonstrations, doctors have now injected a CRISPR treatment directly into eye cells, helping vision-impaired patients see shapes and colors again.

TIGR may supplement CRISPR by providing more refined DNA targeting

The tandem interspaced guide RNA is primarily found in viruses—unlike CRISPR, which is bacterial in origin—and is smaller than CRISPR, making it easier to deliver into cells. The TIGR-Tas system appears to read both sides of the DNA double helix and opens a smaller segment of DNA for repairs, improving the precision of single letter modification.

See how a novel gene editing technique called base editing can create changes in a single DNA base, using a more precise targeting approach than CRISPR-Cas9.

Astronauts have repaired genetic damage in space using CRISPR—a molecular tool that can make precise changes to DNA and is used in single-celled organisms to attack invasive viruses.

CRISPR turns 10 years old

When Dr. Jennifer Doudna and colleagues released a paper in 2012 demonstrating the ability to harness the cell's natural immunity machinery to edit DNA, it received little fanfare. A decade later, the gene editing technology has led to innovations in medicine, evolution, and agriculture—and raised profound ethical questions about altering human DNA.

CRISPR can't fix faulty mitochondria

Gene editing via CRISPR could theoretically fix many issues in biology, but editing the mitochondrial genome has remained challenging. In recent years, there has been some progress reaching these cellular powerhouses. (Some users may experience a paywall.)

Epigenetic editing—altering gene expression by removing or adding chemical groups on DNA—is making significant strides in the lab, even lowering cholesterol in monkey experiments by about 70%. (Free w/email.)

Gene therapy treats a disease by editing the disease's underlying DNA, replacing it with a functional variant.

Advances in agriculture are being powered by CRISPR to boost carbon capture

Researchers are using CRISPR to test thousands of plant gene edits, aiming to speed up breeding and maximize carbon retention in soil. By engineering drought tolerance, they also aim to increase crop yields and expand the environments where crops can grow.

While humans have been genetically modifying plants for millennia by selectively breeding organisms with certain traits, gene-editing tools like CRISPR have further enhanced plants, conferring resistance to drought, pests, and diseases.

Dispose of invading viruses while learning about the CRISPR immune system

In this free, easy-to-play game, defend the city of Bacterium by playing the role of Cris Perotein. As you play, you'll learn microbiology and the workings of the mechanisms that CRISPR uses to protect bacteria. (desktop recommended)

Drs. Jennifer Doudna and Emmanuelle Charpentier discuss CRISPR

Jennifer Doudna and Emmanuelle Charpentier's were awarded the 2020 Nobel Prize for research focused on understanding and adapting the CRISPR-Cas9 system to precisely edit DNA sequences in other organisms. Doudna has indicated that the system can potentially treat genetic forms of blindness and high cholesterol.

Gene therapy, a hope of the Human Genome Project, has successfully treated a baby born with a rare urea cycle disorder that causes toxic ammonia level buildup.

CRISPR technology is removing allergens from common foods

Proteins responsible for allergies to eggs, milk, wheat, peanuts, and other foods can be genetically edited out of foods to reduce the risk of life-threatening reactions. The technique has also been used to produce caffeine-free coffee beans, spicier tomatoes, allergen-free pets, and more nutritious fish.

Synthetic biology can prevent extinction by creating create disease-resilient plants and animals

Through gene editing and the deployment of artificial cells, scientists can leverage learnings from the genetic sequencing of animals with known resistances to protect endangered species. Gene editing of certain species, such as mosquitoes, can also reduce their ability to spread diseases like malaria between humans.

The first CRISPR-approved treatment was for sickle cell anemia in 2023

Victoria Gray was the first patient to receive a CRISPR-based therapy, which eliminated her symptoms and restored her health. The therapy's initial cost of $2.2M has kept it out of reach of many patients.

Malaria mosquitoes in a lab were wiped out using CRISPR

Scientists at Imperial College London disabled a gene in female Anopheles gambiae mosquitoes to make them infertile and propagated the infertility mutation at unnaturally high rates using a gene drive. The entire population collapsed within a dozen generations, showing promise for subsequent with mosquitoes in mimicked tropical environments.

Gene therapy can occur inside the body, but it can also be completed outside the body—with scientists treating cells in the lab, and then those corrected cells are transplanted back into the body.

Researchers are breeding genetically modified mosquitoes to be malaria-resistant.

Research on bacterial cultures used in yogurt production led to CRISPR's discovery

Scientists learned it was a microbial immune system that could be repurposed to protect dairy cultures from viruses. Today, nearly all yogurt is made with CRISPRized bacteria, as are genetically modified crops like herbicide-resistant corn, wheat, and soy.

Changing a single letter in DNA can permanently alter an organism

Genetic mutations occur when cells replicate, which requires a copy of DNA to be created, and involve substituting, deleting, or inserting letters in a cell's genetic code. Mutations can be caused by normal cellular processes, chemical exposure (e.g., carcinogens), or radiation and may result in genetic disorders or genetic variations that drive evolution.

As of February 2025, there are more than 150 clinical trials using CRISPR technology

The clinical trials are designed to determine whether experimental CRISPR-related therapies are safe and effective. The majority of trials involve treatments for blood disorders, including beta thalassemia.

How personalized gene-editing saved a baby's life

KJ Muldoon had a 50% chance of surviving a genetic mutation until doctors developed a one-of-a-kind gene-editing therapy. In an interview with one of the researchers behind the treatment, learn what it will take to make personalized genetic medicine possible for everyone.

Explore the differences between healthy and cancerous cells using a DNA microarray

In this simulation, you will learn how scientists use microarrays to experiment on thousands of genes at the same time. By determining which genes are on or off, users can identify those that contribute to cancer formation.

Advanced drugs are closing in on cancer's deadliest mutations

The protein KRAS, mutated in many cancers, was deemed ‘undruggable’. Now scientists are hoping to save lives with a batch of new compounds that target it.

Scientists create the first CRISPR-modified spider to enhance its silk proteins

A research group at the University of Bayreuth used CRISPR-Cas9 to genetically modify spiders to produce glowing red silk. Spider silk is five times stronger than steel by weight, and this research paves the way for developing new silk functionalities.

Genetic engineering will change everything forever

Designer babies, the end of diseases, genetically modified humans that never age. Outrageous things that used to be science fiction are suddenly becoming reality. As scientists increasingly understand how specific genes cause disease, the possibility of engineering our genes to not only "fix" problems but enhance our natural ability grows.

Move over gene editing, scientists can edit your epigenome

Instead of deleting genes, epigenetic editing modulates their activity. A new paper tests if it’s able to undo a genetic effect of early alcohol exposure.

Why don't we all have cancer?

The creation of a single cell produces 120,000 genetic mutations that can lead to cancer. This video investigates how our bodies proofread and autocorrect those mistakes.

Homology-directed repair is the DNA repair method used by cells

Environmental factors like X-ray exposure may break a strand of DNA, but cells can use a sister strand to patch the damage. Scientists exploit this system by introducing custom DNA templates, which cells use instead to make repairs.

Genetic engineering has accelerated millennia of altering various crops' genes

Although farmers have long cross-bred crops to obtain plants with specific colors, sizes, and other characteristics, these processes took significant time. Today, genetic modification in agriculture involves scientists altering an organism's DNA for various purposes, including enhancing pathogen resistance, removing allergens, and delaying spoilage.