FIG. 3.

Quantitation of tax/rex transcript in NBC-13 cells. BglI- or HindIII-digested products of QC RT-PCR were subjected to electrophoresis and Southern analysis with the X probe. The input of cellular RNA, in nanograms of poly(A)⁺ RNA, and competitor RNA, in femtograms of competitor, and the presence of RT in reaction mixtures are shown above the autoradiographs. An arrow indicates the relative equivalence point. The molecular weight (mw) lane contains a 50-bp ladder with an intense band at 350 bp. BglI digestion yields a 211-bp fragment from tax/rex transcript amplicons, and HindIII digestion yields a 206-bp band from tax/rex competitor RNA amplicons.