Fig. 1.
Internalization of 125I–HAT-SA.
Acid-soluble radioactivity (cell surface bound HAT-SA conjugate) at different times of incubation is shown for the 6 cell lines studied (A). Kinetics of internalization and metabolism of125I–HAT-SA of (B) SP2/Tac or (C) Kit225IG3 cells are shown. Cells were incubated with 125I–HAT-SA for 1 hour at 4°C for surface labeling, then incubated at 37°C for 0, 1, 3, 6, or 24 hours. The relative percentages of radioactivity on the cell surface (acid soluble), intracellularly (acid resistant), and in the supernatant, which is further differentiated by methanol precipitation as free and precipitable, are depicted as a function of time (B,C). Each point represents the mean ± SD of triplicate measurements.
