Figure 7
Quantitative data from flow cytometry showing the intracellular fluorescence and cell surface bound fluorescence of fluorescein-labeled PEG10 K [PEG-(fluo)8], R.I.CK-Tat9 (R.I. Tat9), PEG3.4 K-R.I.CK-Tat9 (PEG-Tat), and PEG10 K-(R.I.CK-Tat9)8 [PEG-(Tat)8] after 24 hrs incubation with MT-2 cells at 37°C for 24 hrs. The total cell associated fluorescence was quantified by flow cytometry. The intracellular fluorescence was measured after the cell surface-bound fluorescence was quenched by 0.2 mg/ml trypan blue at pH 5.8. The cell surface bound fluorescence is the difference between the total cell associated fluorescence and the intracellular fluorescence.