Table 1.
Summary of iPSC inductiona from 6 HDDPC lines through single or repeated (double or triple) transfections of vectors carrying reprogramming factors.
| No. of lines | ALP activityb | Number of electroporations | Appearance of iPSC-like coloniesc |
|---|---|---|---|
| P01 | ++ | Single | + |
| P02 | − | Single | − |
| P03 | − | Single | − |
| P04 | + | Single | − |
| P05 | − | Single | − |
| P06 | + | Single | − |
| P02 | − | Double | + |
| P03 | − | Double | − |
| P04 | + | Double | + |
| P05 | − | Double | − |
| P06 | + | Double | + |
| P05 | − | Triple | + |
aHDDPCs were co-transfected with reprogramming vectors (pCE-OCT3/4, pCE-SK, and pCE-MYC) once, twice, or three times, according to the time-line described in Fig. 1a. After transfection, cells were first cultured in α-MEM + 10% FBS for 15 days and then in iPS cell medium containing β-FGF and 5 factors (PD98059, PD032590, CHIR99021, forskolin, and hLIF), except for P01 in which iPSC medium containing β-FGF and 4 factors (PD98059, PD032590, CHIR99021, and forskolin) was employed.
bALP activity was evaluated by cytochemical staining for ALP activity using fixed HDDPCs. ++, >40% of cells exhibiting strong ALP activity; +, ~10% of cells exhibiting strong or moderate ALP activity; −, no cells showing ALP activity.
cThe presence/absence of iPSC colonies 24 days after final transfection was judged as positive (+) or negative (−). If at least one colony per well was recognised, the well was judged as +.