Fig. 5.

Cell uptake assay of ¹⁸F-FP-QQM in tumor cells. For the blocking experiment, the QQM peptide was added to UM-SCC1 cells in 24-well plates at a final concentration of 1 μM to block the specific binding of ¹⁸F-FP-QQM. To determine the internalized activity, extra groups of UM-SCC1 cells were washed with acid (50 mM glycine-HCl/100 mM NaCl, pH 2.8) to remove the radioactivity bound to the cell surface. The cell uptake is expressed as the percentage of decay-corrected total input radioactivity. All the experiments were performed twice with triplicate wells