Harvard College researchers, led by George Church, have announced that more than 13,000 genetic alterations have been made to a single cell using CRISPR technology. This work is designed to edit genomes at a much larger scale than currently possible, potentially resulting in the “radical redesign” of species or even humans.

During the experiment, researchers attempted to edit LINE-1 components within the body, genetic components which are thought to account for around 17% of the entire genome. This was previously attempted several years ago, when a similar experiment attempted top remove LINE components in a number of mice. None, however, survived to breed.

In order to ensure the fatalities didn’t occur this time, Harvard staff substituted a tailored version of CRISPR which does not remove nucleotides but instead replaces them with another letter. Using this method, the staff made around 13,200 changes to a cell without destroying it.

A company coming out of the lab, eGenesis, has already started to create pigs with numerous edits made to their genomes so that their organs can better be tolerated by humans during transplants.