Cellular Reprogramming Employing Recombinant Sox2 Protein
Figure 2
Effect of media supplements on the stability of cell-permeant Sox2-TAT fusion protein and efficiency of protein delivery. (a) Ability of media supplements to stabilize Sox2-TAT. Fetal calf serum (FCS), Albumax, and serum replacement (SR) were added to the eluate fraction and subsequently dialyzed against DMEM-F12 media. Depicted are anti-Sox2-immunoblots of the dialysis fraction (D) and a stability test of samples being taken after 1 hour (1 h) and 6 hours (6 h), respectively. (b) Influence of FCS, SR, and a combination of both on the transduction efficiency. Protein transduction efficiencies were analyzed by quantifying the recombined cells after delivery of cell permeant Cre-protein (TAT-Cre) into the CV1-5B Cre reporter cell line. Cells were treated with different concentrations of TAT-Cre (0.25 μM–2 μM) in transduction media supplemented with either 15% serum replacement, 5% FCS, or mixture of 2% FCS and 7.5% SR. To determine the recombination activity, cells were fixed and stained for β-galactosidase activity after 48 hours. Cre protein transduction and quantification of recombination in Cre reporter cells was performed as described previously [35].
