CRISPR gene editing changes the sequence of DNA CARLOS CLARIVAN/SCIENCE PHOTO LIBRARY

A team has used CRISPR to make a record-breaking 13,200 changes to the DNA of a single human cell. The feat takes us a step closer to being able to thoroughly rewrite the genomes of our cells and other organisms.

Half of our genomes – the complete set of DNA inside our cells – consist of hundreds of thousands of copies of genetic parasites called transposons. These transposons code for genes that copy and paste themselves from one location in the genome to another. Most copies of …