For the first time ever, researchers have managed to film in real time the astonishing activity of CRISPR on a strand of DNA. The short few seconds of video actually record the molecules interacting as the protein snips the genetic code, confirming what many clever scientists have worked out about the process from other observations. It really is incredible.
It might just look like a grainy gif of some yellow-brown blobs on a dark background wobbling about a bit, but what you are seeing is what many consider to be one of the biggest genetic breakthroughs in recent times. The video shows the CRISPR-Cas9 enzyme (the yellow blob) physically cutting the strand of DNA on which it is sitting (the brown streak).
When the researcher who filmed this, Osamu Nureki, showed the short clip to a group of scientists at a conference, there were audible gasps from around the room. Most of the audience already knew how the process works, but were stunned to be able to watch it occurring in real time. The work has since been published in Nature Communications.
The CRISPR-Cas9 gene editing technique has somewhat taken the biological community – and in more recent times the media – by storm. Due to the precision and speed at which it can cut DNA in the exact place desired and slip in an extra bit of genetic code, it has been used for a whole variety of things, from making super hench beagles to editing a human embryo.
The astonishing clip was achieved using a technique known as high-speed atomic-force microscopy (AFM). The more standard AFM uses a minuscule needle drawn over the surface of what the researchers are trying to image by touch. It can then be used to build up a picture of the molecules in question. But, it has its limitations, as the rate at which an image is recovered is not very fast, meaning that AFM is usually limited to static molecules.
High-speed AFM, however, is able to scan what is being imaged much faster, and thus can capture the dynamic processes of biological molecules like proteins as they change shape and interact in real time. In this case, Japanese scientists were able to turn the high-speed AFM on DNA and watch as CRISPR physically cut the strand in front of them.
The film doesn’t show them anything new, but reaffirms that their calculations were correct, and proves just how incredible the CRISPR technique actually is.