In a brief, blocky, but stunning video released recently, scientists have witnessed a powerful gene editing technique in action.
CRISPR, also known as CRISPR-Cas9, is a tool that, in conjunction with an enzyme known as Cas9, modifies genes by cutting strands of DNA, allowing traits to be deleted or new ones to be inserted. It has the potential to make malaria resistant mosquitos, treat HIV in mice, and eliminate some genetic diseases, among other things. Like many biological processes, biochemists have had to tease out CRISPR’s details without ever directly seeing it.
For a molecular-scale video clip, it shows amazingly clear footage in real time of CRISPR breaking DNA in two.
Osamu Nureki, author of the paper and accompanying video clip, has previously used X-ray crystallography to study Cas9’s structure. To do that, he and his colleagues would coax Cas9 into a crystalline form and then they bombard them with X-rays, inferring the structure by studying how the rays diffracted. The result was a static, computer-generated image.
In this new study, Nureki and his team “filmed” CRISPR-Cas9 using a unique type of microscopy. Here’s Sarah Zhang for The Atlantic:
His team used a technique called high-speed atomic-force microscopy, in which a tiny needle moves back and forth probing the shape of Cas9. The needle moves so fast that it produces a movie. “The result is fairly easy to understand,” says Hiroshi Nishimasu, one of Nureki’s collaborators on the paper. “People say, ‘Wow!’ It’s very simple.”
When Nureki presented this video for the first time at a conference in Big Sky, Montana, there was reportedly a gasp from attendees in the room—a rare occurrence at scientific proceedings.