Figure 4.

(A) The uptake in either C6 cells or C6–790 cells is plotted against time for four different [¹²⁵I] tracers: the unconjugated antiluciferase PNA (designated PNA^Luc), the unconjugated anti-rev PNA (designated PNA^rev), the PNA^Luc conjugated to OX26/SA, and the PNA^rev conjugated to OX26/SA. Data are mean ± SE (n = three rats) for each time point. (B) Film autoradiography after SDS/PAGE of C6–790 cell extracts obtained at 4 (lane 1), 6 (lane 2), or 24 (lane 3) h incubation with either the PNA^rev conjugate (Left) or the PNA^Luc conjugate (Right). (C) Pulse–chase experiment showing rate of loss of radioactivity from the cellular TCA precipitable fraction during a second 24-h period after the C6 cells or C6–790 cells were pulsed during an initial 24-h incubation with the labeled PNA^Luc conjugate. Data are mean ± SE (n = three dishes) for each time point. The radioactivity was significantly higher in the C6–790 cells at all time points (* indicates P < 0.01, Student's t test).