[titanomachy]

"Synthetic biology" in technical usage refers to custom sequences which are written on a computer then chemically assembled ex vivo. This is a widely used technique. It is distinct from the technique of extracting and amplifying a sequence from one organism and inserting it into another, although the results produced can be similar.

Source: I work in a molecular biology lab.

[Dylan16807]

So let's say there's a gene that might be useful to me. I have a listing of base pairs, but it would be very expensive to extract DNA/RNA from actual specimens. I chemically assemble an exact recreation and inject it. Is this synthetic biology?

[titanomachy]

Yep! Although the result might be the same, the technique used is synthetic biology. Usually the synthetic route is more expensive but a lot simpler.

[xkcd-sucks]

So would PCRing a mutation into a gene be synthetic biology, or only if you wrote out the sequence on a computer before buying primers?