TABLE 2.

Formation of ura⁺ recombinants depends on Cre recombinase and two loxP inserts

Position of loxP insert		Recombination frequencya
padh1-loxP	loxP-ura4	−Cre	+Cre
arg1	arg1	<0.00022	79 ± 16.5
arg1	lys4	<0.00017	4.5 ± 1.5
None	arg1		0.16 ± 0.16
None	lys4		0.06 ± 0.02
None	arg7		0.03 ± 0.02
None	his1		0.05 ± 0.01
None	lys3		<0.006

Each value represents the average of three measurements.

^aExpressed as the number of ura⁺ recombinants/10³ CPU.