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

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.

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.

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.

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 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.

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.

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 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.

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.

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.

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.

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.

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.

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.

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.)

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.

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.

Women's wartime suit features silk dyed with CRISPR-modified bacteria

Anna Dumitriu's bioart piece was created to commemorate the 75th anniversary of the first use of penicillin in a human patient and intends to raise awareness about the rapid development of antibiotic-resistant pathogens by using bacteria that have essentially been transformed into their pre-antibiotic era state.

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.

Rosalind Franklin’s work led to Nobel Prize-winning discoveries in DNA and virology

Her X-ray diffraction imaging helped uncover the structure of DNA, which earned James Watson, Francis Crick, and Maurice Wilkins a Nobel Prize. The same techniques enabled virus imaging, contributing to Aaron Klug's Nobel Prize in chemistry.

An estimated 1% of DNA mutations in bacteria can produce more dangerous strains

Researchers have developed a technique to monitor these mutations in real time. Using this technology, scientists found that mutations occur at a steady rate, with 1% leading to potentially deadly changes.

In 2025, researchers in the UK began working on developing artificial DNA

The Synthetic Human Genome Project aims to one day construct human DNA, molecule by molecule, in the hopes of creating disease-resistant cells and synthetic chromosomes for study. However, critics warn it may be misused to create enhanced or modified humans.

Watch how Sanger sequencing kickstarted the first generation of DNA sequencing

Sanger sequencing is a foundational DNA sequencing technology developed in 1977. The Nobel Prize-winning discovery uses fluorescent dyes at the end of DNA chains, which are sorted by length through electrophoresis, to determine the order of nucleotide bases.

Mosquitoes are the world's deadliest animal—gene drives could kill them

Historically, killing all disease-carrying mosquitoes has not seemed practical and there are concerns about disrupting food webs. Gene editing to render female mosquitoes infertile creates the theoretical possibility of wiping out disease-carrying species, but concerns remain about effectively limiting this engineered trait to target species.

How Nobel Prize-winning research unraveled why the immune system doesn't always attack itself

The 2025 Nobel Prize was awarded to scientists who discovered how immune system soldiers are typically stopped from attacking healthy tissue. The work furthered autoimmune understanding and cancer therapies.

Genetically modified viruses can help construct battery electrodes

MIT scientists' modifications caused the viruses to attract conductive materials, such as gold ions, which the viruses self-assembled into nanowires that could be used in batteries. These components allow batteries to be thinner and flexible enough to be constructed into new shapes.

RNA may have allowed life to exist before DNA

The emergence of living organisms from non-living matter—abiogenesis—requires both a molecule that encodes genetic information and proteins that perform biochemical processes. However, because DNA and protein depend on one another, some biologists theorize that RNA, which can both store information and perform functions, preceded both and originated life.

The first line of 'immortal' human cells, which can divide indefinitely and are used in scientific research, was nonconsensually taken from a Black woman.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

Radioactive elements can introduce software errors because the ionizing radiation they produce can detach electrons from atoms, and computer code relies on the distribution of electrons.

Read a deep dive on the 'all-purpose healing' peptide BPC-157.

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

Larger animals like giraffes, elephants, and blue whales have developed a unique defense against cancer, a phenomenon known as Peto's Paradox

The 2026 Ebola outbreak in the DRC is spurring new Ebola vaccine development for the Bundibugyo species.

English mathematician Ada Lovelace wrote the first computer algorithm a century before computers existed and hypothesized that computing devices would one day be able to compose music—foreseeing the generative AI systems of today.

Budweiser stores yeast derived from the original 1800s strain in a secret bunker, which only the Head of Yeast Management can access—not even the CEO

The hormonal disorder PCOS was renamed PMOS in 2026, a move designed to improve care and research by shifting the focus to the hormonal causes of this condition that affects 1 in 8 women.

Long before Major League Baseball began allowing instant replay for balls and strikes, an umpire reluctantly used the technology to determine whether a hit was a home run, a move that inadvertently ushered in a new era for the sport.

Massive blooms of microscopic plankton called dinoflagellates produce the neon blue light seen in glowing tides.

Crows are believed to have intelligence on par with a seven-year-old child and demonstrate complex behaviors, from problem-solving with tools to recognizing human faces.

In 1984, Operation Smash Hit intentionally crashed a 239-ton train into a nuclear waste canister at 100 miles per hour to prove the canister's safety, which remained completely intact and lost just 0.29 of its 100 pounds of pressure.

To reduce wrinkles in clothing, research recommends gentle wash cycles with more water and tumble drying with smaller loads and longer times.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

Brandi Chastain, the star of the 1999 US victory over China in the 1999 Women's World Cup, was a last-second choice to take the penalty kick that sealed the victory.

Hotels in Cannes, the glamorous city on the French Riviera, hire hawks to ward off seagulls during the city's famous film festival.

Fast-casual restaurant Chili's is experiencing a resurgence, with its parent company recently reporting a nearly 32% increase in sales, thanks to passionate Gen Z fans on TikTok.

During the French Revolution, a botanist's letter asking about "dear Rhus" (poison ivy) was intercepted, leading authorities to suspect he was conspiring with the Russians.

Sony set the standard for cylinder-shaped batteries when it repurposed manufacturing equipment used to make rolls of magnetic recording tape.

Explore the archaeological treasures of Pompeii, the city buried under volcanic ash when Mount Vesuvius erupted in 79 CE.

Prince's sexually explicit 1984 track 'Darling Nikki' attracted the ire of the Parents Music Resource Center, an advocacy group that inspired the Parental Advisory sticker, even though the song ends with a Christian message.