The Ars article has some more details: https://arstechnica.com/science/2019/05/researchers-make-their-own-e-coli-genome-compress-its-genetic-code/ https://arste

The Ars article has some more details: https://arstechnica.com/science/2019/05/researchers-make-their-own-e-coli-genome-compress-its-genetic-code/ https://arstechnica.com/science/2019/05/researchers-make-the... > Unfortunately, there's a big gap between what a DNA synthesis machine can output and the multi-million-base-long genome. The group had to do an entire assembly process, stitching together small pieces into a large segment in one cell and then bringing that into a different cell that had an overlapping large segment. "Personally, my biggest surprise was really how well the assembly process worked," Schmied said. "The success rate at each stage was very high, meaning that we could do the majority of the work with standard bench techniques." > During the process, there were a couple of spots where the synthetic genome ended up with problems—in at least one case, this was where two essential genes overlapped. But the researchers were able to tweak their version to get around the problems that they identified. The final genome also had a handful of errors that popped up during the assembly process, but none of these altered the three base codes that were targeted. So it sounds to me like the process wasn't quite perfect. They also note that DNA "redundancy can also allow fine-tuning of gene activity, as some codes are translated into proteins more efficiently than others".