A longtime goal of cell engineering is to modify a living cell in a directed fashion. Earlier this year, Cellectis S.A. said it could make in vivo changes to DNA using its Meganuclease Recombination System. Last week it was joined by Sangamo BioSciences Inc., which reported it has achieved this goal without using a reporter gene or selection sequences to confirm the insert’s integration in the genome.

The new report in the Proceedings of the National Academy of Sciences describes the use of Sangamo’s zinc finger nucleases (ZFNs) to transfer an 8kb segment of DNA to a predetermined endogenous