Figure 2.

Efficiencies of gene transduction and generation of alkaline phosphatase (ALP)⁺ colonies. (A) Gene transduction efficiencies of amphotropic retrovirus infection. Efficiencies were estimated on day 3 postinfection by qRT-PCR and are shown in comparison with those in DFBs (mean ± SD, 3 independent experiments). Statistical significance was determined by Scheffe's test after ANOVA (*p < 0.05, **p < 0.01). (B) Generation efficiency of ALP⁺ colonies. (Top) Representative result of ALP⁺ primary colonies (blue) emerging from 2.5 × 10⁴ infected cells on a 6-cm culture dish (mean ± SD, 3 independent experiments). (Bottom)Efficiencies of retention of both the human embryonic stem cell (hESC)-like morphology and ALP activity in secondary colonies. Efficiency was determined by dividing the number of secondary colonies by the number of primary hESC-like colonies emerged on two 10-cm dishes. ●Independent results from 5 DFB experiments (DFB01, DFB18, DFB22, DFB37, and DFB44), 3AMC experiments (AMC41 and a duplicate of AMC49), and 12 DMC experiments (DMC41 and duplicates of DMC54, DMC70, DMC71, DMC72, DMC73, DMC75, DMC76, DMC77, DMC83, and DMC92). ?Mean value. Statistical significance was determined by Scheffe's test after ANOVA (*p < 0.01). See Table 1 for gene definitions.