Fig. 7. UV-crosslinking of p40/50 to nuclear and cytoplasmic poly(A) RNA in vivo. Nuclear (N) and cytoplasmic (C) extracts were prepared from both UV-irradiated (+UV) and control (–UV) tissue culture cells. The crosslinked proteins were collected with oligo(dT) chromatography, fractionated by SDS-PAGE and analysed by western blotting. Antibodies against p40/50 and hrp36 (positive control) were used in the western blot.