Patent ID: 7074611

Claim:
An isolated DNA molecule comprising a sequence A flanked by site specific recombinase targeting sequences (SSRTS) L1 and a sequence B flanked by site specific recombinase targeting sequences (SSRTS) L2, said SSRTS L1 and SSRTS L2 being unable to recombine with one another, wherein: i) sequences L1 are in an orientation opposite one another, wherein said sequences point towards each other or away from each other, ii) sequences L2 are in an orientation opposite to each other, wherein said sequences point towards each other or away from each other, iii) the order of the sequences in said isolated DNA molecule is 5â€²-L1-L2-sequence A-sequence B-L1-L2-3â€², and iv) at least one of sequence A or sequence B encodes a protein.