(CNN) - Look miles into the future and imagine a day when geneticists can design a flawless set of human genes in a laboratory.
That future vision may never arrive, but it has taken a step closer.
Scientists have built a designer chromosome and inserted it into a cell, geneticist Jef Boeke from New York University announced this week.
The chromosome was a heavily altered version, a departure from its natural counterpart. A team of scientists from around the world made 500 changes to its genetic base.
But the cell survived and made use of its new chromosome. It also reproduced, and subsequent cells carried the new chromosome forward.
Actually, make this breakthrough a second step closer to that way-out-there future.
Researchers were already able to duplicate a chromosome on a computer four years ago, build it in the lab, insert it into a cell and watch it work.
It was a huge advancement that created the first synthetic bacteria cell, scientists said then.
But, now, there's been a leap forward, Boeke said.
It makes scientists more able to alter the design of living things.