Patent ID: 7223601

Claim:
A method for integrating a DNA of interest into the genome of a eukaryotic cell comprising: a) introducing into said eukaryotic cell a transfer cassette comprising said DNA of interest, wherein said DNA of interest is flanked by a target site for a first site-specific recombinase and a target site for a second distinct site-specific recombinase, wherein said first and said second target sites are non-identical: and, said genome of the eukaryotic cell comprises an integration site comprising said first target site for said first site-specific recombinase and said second target site for said second site-specific recombinase; and, b) providing in said eukaryotic cell said first site-specific recombinase, an active variant of said first site-specific recombinase, or an active fragment of said first site-specific recombinase; and, said second site-specific recombinase; an active variant of said second site specific recombinase, or an active fragment of said second site-specific recombinase; wherein said active variant and said active fragment of said first and said second site-specific recombinase catalyze a recombination event.