Fig. 2. Schematic illustration of implementation of CRISPR-PUFs.

Using CRISPR-Cas9 system, a set of synthetic constructs containing an array of 5–base pair (bp) barcodes (5′-NNNNN-3′), constitutive fluorescent reporter, and hygromycin resistance gene was stably integrated into the human AAVS1 safe harbor locus. Next, the cells were transiently transfected with CRISPR to induce NHEJ.