Figure 4.

Uptake of fluorescein-labelled oligodeoxynucleotide (ODN) in RAW264.7 cells. Cells were incubated with fluorescein-labelled double-stranded ODN (dsODN) (○), dsODN × 3 (△) or Y-ODN (•) for 1 hr at 4° or 37°, and the amounts of ODN associated with cells were measured by flow cytometry. The mean fluorescence intensity (MFI) was plotted against the concentration of ODN. Results are expressed as the mean ± SD of three determinations. *P < 0·05, **P < 0·01, significantly different from dsODN and dsODN × 3.