Analysis of LoxP parent cell lines. (A) Clones from the high GFP-expressing pool (Figure 1B) were grown in the presence of 100 ng/ml Dox. Media containing Dox was removed 7 days prior to analysis and media changed daily before GFP expression analysis by FACS. (B) Clone B3 contained two sub-populations (A = not expressing GFP; B = expressing GFP), which were separated by FACS. The ability of Clone B3-B cells to be induced to express GFP was analysed at day 0 post-sorting, day 30 and day 55, with Dox removal at each time point as panel A.