Recombination assembly of large DNA fragments

A method of assembling large DNA fragments in a chromosome using site specific recombinases and alternating excisionases. The method may be performed in vitro or in vivo, but larger assemblies are possible when the assembly is performed in vivo. For an in vivo assembly, the cell must be engineered to contain the desired recombinases, each in an inducible construct so that the desired recombinase can be expressed at the correct time with the correct choice of inducing agent