Identification of clones with desired phenotype. (a) Individual clones were grown in the presence (open peaks) or absence (filled peaks) of Dox for 6 days and then stimulated to examine CD69 expression by FACS. The 'Dox ratio' was defined as the ratio of CD69 geometric mean fluorescent intensity in the presence of Dox divided by CD69 geometric mean fluorescent intensity in the absence of Dox and is indicated in parentheses following the clone number. (b) DNA oligonucleotide primers specific to the library vector (BstXTRA5G and BstXTRA3D, not to scale) were used in RT-PCRs to recover the cDNA inserts from cell clones. The RT-PCR products were analyzed in agarose gel followed by ethidium blue staining. Data from representative clones are shown alongside the 1 kb DNA molecular weight ladder (Mr) from New England BioLabs (Beverly, USA).