Efficient disruption of CCR5 ex vivo and detection of CCR5-modified cells in vivo. (A-B) A small aliquot of electroporated HSPCs from 4 animals transplanted with mCCR5 ZFNs was maintained ex vivo to quantify bulk and biallelic disruption of CCR5. (A) Total gDNA isolated from ex vivo cultured HSPCs; displayed is the peak disruption during a 5-day liquid culture time course. (B) Biallelic disruption was measured in colony forming assays as described in “Materials and methods.” (C) Peripheral blood was collected from each animal at the indicated time points post-transplant, and gDNA was isolated from hemolysed total leukocytes. (D) GI biopsies were collected from the indicated animals at ∼190 days post-transplant and total gDNA was isolated. Duodenum/Jejunum biopsies were not collected from Z12161 and Z12220 due to insufficient size of the animals. CCR5 disruption was measured from each gDNA sample by Illumina MiSeq. “Control” are representative values from 1 of 3 CCR5 WT animals from which GI tissues were collected following transplant with lentivirus-transduced cells. All values are significantly increased relative to the controls at the P < .05 level of significance (Bonferroni-corrected).