Figure 2.

Activity of the CS series of ZFNs determined by a SSA assay. The number of fingers in the left and right arrays for each ZFN are indicated. Note that the CS3-1, 5-1, 6-1, and 6-2 series started with four- or six-finger arrays instead of three-finger arrays to reduce the assembly effort required prior to the invention of the drop-out linker strategy. Based on the data, the missing ZFNs seemed likely to be inactive and were not tested subsequently. (-) SSA reporter only as a negative control. (Ctrl) GZF3-L3 + GZF1-R3 control nuclease to which all activities are normalized. (Error bars) The standard deviation of normalized duplicates from at least two experiments. (*) P < 0.01 compared to the negative control based on a one-tailed homoscedastic t-test. (Black arrows) ZFNs used in genomic cleavage assays.