Lack of bcl-2 mRNA in FVA cells. (A) The steady state levels of mRNA detected by a probe specific for bcl-2. The first three lanes contained RNA taken from cells of a MEL cell line. From left to right, each lane contained 20 μg of total cellular RNA from control cells and from cells after 4 and 5 days of exposure to 2% dimethyl sulfoxide (added to induce differentiation of the cells). The last four lanes on the right each contained 20 μg of total RNA taken from EP-treated (+) or EP-deprived (−) FVA cells at 2 and 4 hours. (B) A photograph of the formaldehyde/agarose gel stained with EtBr to show the RNA in the lanes.