Genome-edited primary CD34⁺cells display survival advantage and clonal expansion in vitro. (A) Representative growth curves chart the differences in proliferative capacity of genome-edited CD34⁺ cells compared with controls (GFP or MLL TALENs alone). Arrows indicate time point of FISH analyses and karyotyping. (B) Graph shows cell viability in liquid culture monitored over time by flow cytometry and further confirmed by trypan blue dye exclusion. (C) PCR was performed for MLL-AF9 and reciprocal AF9-MLL breakpoints on genomic DNA over progressive time of culture. (D) Representative morphologies are shown for control and translocated cells on day 76 by May-Grünwald-Giemsa staining. Arrowheads indicate differentiating cells. Scale bar, 20 μm. (E) Colony-forming assays were performed on day 60 of liquid culture. Bars represent the mean number of colony-forming units (CFUs) per 10⁴ seeded cells. (F) Plot indicates cell numbers after each replating. Experiments were performed in triplicate, and data from 2 independent experiments are shown. (G) Images show representative morphologies of colonies after each replating (R). Scale bar, 200 μm.