Fig. 2.

Selection of GGTA1 and CMAH gene bi-allelic DKO cell colonies. (A) Cell colonies were selected and subjected to two rounds of T7E1 Surveyor assays. The first round (left, PCR products of the candidate colonies were digested by T7E1) excluded heterozygotes, and the second round (right, PCR products of the candidate colonies and wild-type cells were mixed and then digested by T7E1) identified the candidate homozygotes. * indicates T7E1-digested fragments of the #8 cell colony at the GGTA1 and CMAH loci. (B) PCR amplicons of GGTA1 (left) and CMAH (right) loci of the #8 cell colony and wild-type cells. (C) Genotypes of the #8 cell colony at the GGTA1 and CMAH loci. PAM sequence is underlined.