biology

Here's CRISPR's dirty secret: it works by breaking things. When Cas9 edits a gene, it doesn't delicately rewrite the code. It takes molecular scissors and snaps both strands of the DNA helix in half. Then it stands back and lets the cell's

Bacteria have been at war with viruses for three billion years. Think about that timeline. Bacteria were fighting off invaders before there were plants, before there were animals, before there was oxygen in the atmosphere. And somewhere in that unimaginably long arms race, they evolved something remarkable: an immune system

Bacteria have been fighting viruses for three billion years. Somewhere in that war, they evolved something extraordinary: an immune system that remembers. It keeps molecular mugshots of every virus that's ever attacked, and if they show up again, it hunts them down with programmable precision. In 2012, two

Here's what keeps CRISPR researchers up at night: You design a guide RNA to target a specific gene. Twenty letters of genetic code. You've checked it carefully. The target is unique in the genome—or at least, unique enough. You run your experiment. The cut you

Victoria Gray remembers the pain. Not just remembers—her body remembers. Thirty-four years of sickle cell crises, episodes where her blood cells jammed in her vessels like a traffic pileup, starving her tissues of oxygen. The pain would come like being stabbed with hot knives, she said. It would last

Mosquitoes kill more humans than any other animal on Earth. Not sharks. Not snakes. Not other humans. Mosquitoes. Specifically, the Anopheles mosquitoes that carry malaria parasites and the Aedes mosquitoes that spread dengue, Zika, and yellow fever. Every year, malaria alone kills over 600,000 people—mostly children under five