Effects of oligonucleotides on differentiation of CD34⁺ cells induced with FL plus IL-3 assayed by immunocytochemistry. Cells at an initial concentration of 5,000/mL were incubated in medium supplemented with FL at 50 ng/mL and IL-3 at 25 ng/mL to promote monocytic differentiation. On days 0, 5, and 10, antisense RB oligonucleotides (AS2), sense-orientated oligonucleotides (SO2), scrambled oligonucleotides (SCR), or oligo buffer were added, each time at a concentration of 5.0 μmol/L. After 14 days, cytospin slides were subjected to immunochemistry using antibodies to human lactoferrin, as described in Materials and Methods. Red-colored cytoplasm indicates the presence of lactoferrin, a granulocyte-specific protein. Cells incubated with FL, IL-3, and buffer (A); with FL, IL-3, and SO2 (B); with FL, IL-3, and SCR (C); with FL, IL-3, and AS2 (D); and human neutrophils (E).