On Nov. 15, 2016, the National Institutes of Health (NIH) issued guidelines for DNA splicing. The guidelines set safety requirements for NIH-funded research involving the splicing together of pieces of DNA from two species and its reinsertion into a living organism.

They followed a two-year voluntary moratorium on this type of research initiated because of concern among scientists about the potential dangers of organisms containing this recombinant material. The NIH guidelines place varying physical and biological restrictions on these experiments, depending on the anticipated hazard of the research.