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

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 technology has improved crop resistance to pests and diseases

The gene editing tool is a modern version of the genetic modification that has been done on crops for centuries to create plants with preferred traits. Other applications of CRISPR include creating plants with higher yields and better resistance to climate challenges, as well as foods with improved shelf life and nutrition.

Visualize how CRISPR-Cas9—a type of immune system used by single-celled organisms to attack invasive viruses—targets and makes precise changes to a gene's DNA.

Visualize how CRISPR works at the molecular level

CRISPR is a revolutionary gene-editing technology already making a real-world impact in helping to treat several diseases and conditions. This simulation provides a microscopic view to help easily visualize the complex science.

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.

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.

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.

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.

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.

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.

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.

Gene therapy, a hope of the Human Genome Project, saves a baby's life

A baby with a rare genetic disorder received a bespoke gene-editing treatment using CRISPR technology. The case highlights the potential of personalized medicine for rare diseases, building on the foundation set by the Human Genome Project.

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.

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.)

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.

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.

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.

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.

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.

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.

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.

Gamma Knife surgery uses incredibly precise, high-energy light to treat patients

A form of brain stereotactic radiosurgery, this non-invasive technology concentrates beams of light onto specific tumors to damage the DNA of malignant cells, killing them. The gamma rays used are in the same part of the electromagnetic spectrum as those produced in nuclear reactions, cosmic ray collisions, and radioactive decay.

How to turn any cell of the body into a stem cell

Scientists have developed techniques allowing them to 'reprogram' any cell in the body into an induced pluripotent stem (iPS) cell, which can be used to create either more stem cells or specialized cells for use in experimental medical treatments. This page gives readers a brief introduction to the history of iPS cells, what researchers are studying with iPS cells, and challenges associated with iPS research.

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