Recombinant DNA research is regulated by the NIH in the US
The National Institutes of Health publishes a document called The NIH Guidelines for Recombinant DNA and Gene transfer
The guideline is locally translated into ordinance and an enforcing body is set up. In the case of Cambridge, MA that authority is the Cambridge Biosafety Committee
. Their page is informative.
It seems experimenting with recombinant DNA may involve a procedure of applications, permits and fees. I haven't had time to try to understand exactly what requires permits, what the exceptions are and how difficult the permits are for a DIY:er to obtain.
I need to check how it works here(in the EU). It should work more or less along the same lines.