Fig. 2. Isolation of cells expressing AhR sense mRNA or antisense mRNA. (A) Western blot analysis of AhR was performed on whole cell extracts (5 µg of protein for cells expressing AhR sense mRNA (S) and 15 µg of protein for cells expressing AhR antisense mRNA (AS)) that were resolved by electrophoresis on 10% SDS/polyacrylamide gel. (B) The cell clones were treated with 1 µM 3-methylcholanthrene (3-MC) for 12 hours. Total RNA was purified and the level of CYP1B1 mRNA was determined by northern blotting. Results are representative of three separate experiments. The analysis was reproduced twice with similar results. AS, cells expressing antisense mRNA; S, cells expressing AhR sense mRNA; TfR, Transferrin receptor; V, cells expressing vector mRNA.