FIG. 4.

Northern blot analysis of mRNAs transcribed from bicistronic plasmids. RNA was extracted from untransfected C6 cells and from the same stably transfected C6 pools used in the experiment in Fig. 3. A 20-μg portion of each RNA was electrophoresed in two parallel lanes, blotted, and hybridized with either a LUC-specific probe (A) or a SeAP-specific probe (B). To ensure equal loading, rRNAs were stained with methylene blue prior to hybridization. Lanes: 1, untransfected C6 cells; 2, B/0; 3, B/UTR; 4, B/BiP.