Figure 6: RNAi analysis of Oct-4’s role in maintaining pluripotency. siRNAs directed against Oct-4 effectively reduced Oct-4 expression in >90% of cells, as compared to persistent Oct-4-positivity in >70% of control colonies. The Oct-4 siRNA effectively reduces Oct-4 (red) expression in cells inside the colony, and induces concomitant reduction of HDAC1 (red) expression and differentiation, as indicated by the expression of Nestin (green). These Oct-4 knocked-down cells also showed strong histone H3 and H4 acetylation (acH3 and acH4, green) and strong expression of p300 (red), Brg-1 (red), and hSNF2H (green). The Insets are DAPI-stained (blue) colonies shown that cells were present but immuno-negative for the respective antibody.