Human genome synthesis

Scientists are learning to write the entire human genome from scratch, building chromosomes letter by chemical letter in the laboratory. The problem is a massive gap in scale. Researchers can already synthesise bacterial genomes, which are about a million letters long. A human genome is three billion letters—three thousand times larger. No existing technology can build something that big. This project aims to close that gap by developing the tools and methods needed to assemble human-scale DNA. If successful, the work will transform fundamental biology. Scientists could design custom human chromosomes to test how genes interact, how genomes evolve, and how DNA sequence influences disease—questions that are nearly impossible to answer with natural genomes alone. The team will demonstrate their approach by synthesising a single recoded human chromosome, proving the technology works. This is fundamental science. There is no immediate medical or commercial application. But the ability to build any genome on demand would open up possibilities that are hard to predict—much like the first DNA sequencing methods did decades ago, before they became essential tools in medicine, agriculture, and forensics.