Table 2. Effect of the flippase recombination target (FRT) site number on CIGMC efficiency.

Integrated copy number	Number of strains
	GPF-1	GPF-2	GPF-3	GPF-4	GPF-5
1	50	43	38	33	28
2	40	43	45	32	38
3	36	24	28	26	21
4	16	23	16	25	19
5	8	10	8	13	10
6	Nda	4	6	9	12
7	Nd	3	4	4	6
8	Nd	Nd	3	3	4
9	Nd	Nd	2	3	5
10	Nd	Nd	Nd	2	2
11	Nd	Nd	Nd	Nd	2
12	Nd	Nd	Nd	Nd	3
Average integrated copy number	2.28	2.59	2.81	3.29	3.75

For each target strain, 150 clones were randomly selected to determine the integrated copy number of pG-2. The final concentration of pG-2 was 20 ng/μL.

^aNot detected.