Figure 2.

Intracellular accumulation of fluorescein-labeled D series oligonucleotides in eukaryotic cells mediated by Lipofectamine 2000 or under carrier-free conditions

(A) Accumulation of D1-D4 in A549 cells in the absence of transfection agents. (B) Lipofectamine 2000-mediated delivery of D1-D4 in A549 and MDCK cells. (C) Intracellular accumulation of D5-D7 in A549 and MDCK cells under carrier-free conditions. (D) Lipofectamine 2000-mediated delivery of D5-D7 in A549 cells and MDCK cells. Under carrier-free conditions A549 cells and MDCK cells were incubated in the presence of oligonucleotides D1-D4 at concentrations of 0.1–5 μM or oligonucleotides D5-D7 at concentrations of 5 μM for 4 h. In the case of liposome-mediated delivery A549 and MDCK cells were incubated with complexes formed by oligonucleotides D5-D7 (1 μM) with Lipofectamine 2000 for 4 h. The percentage of fluorescent cells was measured by flow cytometry 4 h post-transfection. Data are presented as mean ± SEM. The data were statistically processed using Student's t test (two-tailed, unpaired); a p value of ≤0.05 was considered to indicate a significant difference; ∗∗data were statistically insignificant. All experimental points were run in triplicate for statistical analysis. C1, control, cells incubated without oligonucleotides; C2, control, cells incubated without Lipofectamine 2000; C(LF), cells incubated with Lipofectamine 2000.