Cellular uptake of fluorescein-labeled GRN163 oligonucleotide into lymphoma and myeloma cell lines. Fluorescein-tagged GRN163 oligonucleotide (10 μM) was added to cultured cells in the absence of additional cationic lipids or permeabilizing agents. Cells were removed at various time intervals, washed with PBS to remove unbound oligonucleotide, and analyzed by flow cytometry. Shown are representative cellular uptake levels in 3 cell lines (CAG, HT, U266; panel A) and CD138⁺ MM cells from 2 patients (B).