Targeted transient knockdown of Dicer expression using siRNA. Transfection of 30 nM siRNAs targeting Dicer and non-targeting control (NT) was performed in CHO-K1 8 mM and DUKXB-11 Epo cells. Cells were analyzed 72 h post-transfection: Dicer transcript levels (a) were analyzed by qPCR (n = 3, Actb used as reference gene, error bars represent s.d. of mean). The impact of Dicer down-regulation on mature miRNA levels was analyzed in DUKXB-11 Epo cells by qPCR (n = 3, Actb used as reference gene, error bars represent s.d. of mean). Effect of Dicer knockdown on viable cell density (VCD) and viability of DUKXB-11 Epo (c) and CHO-K1 8 mM cells (d) is shown after 72 h (n = 3, error bars represent s.d. of mean). Significance tests were performed using pairwise Student’ T-test between non-targeting control (NT) and transfected samples (siRNA). Significant differences (p < 0.05) are marked with an asterisk (*).