Fig. 3. E2F-1 expression in synchronized or TGF-ß1-treated preapoptotic G₁ cells determined by northern or western blot analysis. (A) Representative northern blot of 15 µg of total RNA hybridized with a 0.7 kb EcoRI/BglII E2F-1 cDNA fragment labeled with digoxigenin-dUTP detected using the DIG/Genius^TM system as described in Materials and Methods. (B) Whole cell lysates were prepared and subjected to western blot analysis using primary monoclonal C-20 anti-E2F-1 antibody. The proteins were detected using a horseradish peroxidase conjugated secondary antibody and ECL^TM as described in Materials and Methods. The cell cycle phase is indicated at the top. TGF-ß1, preapoptotic cells following 72 hours of incubation with TGF-ß1.