CRISPR Gene Editing Developed
Jennifer Doudna and Emmanuelle Charpentier published the CRISPR-Cas9 gene editing technique
June 28, 2012
Molecular Scissors
In June 2012, Jennifer Doudna at UC Berkeley and Emmanuelle Charpentier in Germany published a paper describing how a bacterial immune system called CRISPR-Cas9 could be repurposed as a precision gene editing tool. The technique uses a guide molecule to direct a protein (Cas9) to a specific location in DNA, where it cuts both strands cleanly. The cell's repair machinery then either disables the gene or replaces it with a new sequence. It was faster, cheaper, and more precise than anything before it.
Why It Matters
Before CRISPR, gene editing was slow, expensive, and imprecise. CRISPR made it fast enough to do in a small lab and cheap enough for widespread research. Within years, researchers were using it to treat sickle cell disease, develop cancer therapies, make crops disease-resistant, and study genetic causes of conditions from blindness to diabetes. In 2023, the first CRISPR-based medicine — a treatment for sickle cell disease — was approved by the FDA.
The Ethical Frontier
In 2018, a Chinese scientist announced he had used CRISPR to edit the genes of human embryos, producing twin girls with modified DNA — the first genetically edited humans. The announcement caused international outrage; he was sentenced to prison in China. The incident opened urgent questions about whether gene editing of human embryos should ever be permitted, and who gets to decide. Doudna and Charpentier won the Nobel Prize in Chemistry in 2020 — the first all-female team to win a science Nobel.