Figure 7. HR strategy to generate cell lines with higher expression of the GOI.

(A–E) Compared with the cell pools and clones derived by traditional selection, the growth of the cell pool and single cell clones selected by the HR strategy remained stable (A, C). In contrast, the Qp and total titer of TNFR-Fc was significantly increased in cell pools and clones generated by the HR method (B, D, E). Black columns are cell clones obtained by the HR strategy; light gray columns are cell clones selected by the traditional method (E). (F) Verification of authentic exchange events for the two cell clones derived by the HR strategy. PCR was performed on 1D1 and 1D1-S2 cell pools and all 8 single-clones with primer pairs as indicated in Fig. 5B. Negative controls were CHO cells and H₂O. Positive controls were SEGFP and HR vectors. The band-shift in all cell clones indicated the SEGFP could be replaced by TNFR-Fc by site-integration exactly.