Northern and RT-PCR analysis in vivo. (a) RT-PCR for the detection of vector expression in BT-474 cells implanted in nude mice. One μg total RNA from variably treated tumor tissue was used as RT-PCR template. The control samples on the left side of the gel demonstrate the integrity of the RNA templates. The bands at approximately 300 bp seen on the right side of the gel correspond to the adenoviral vector cDNA amplicon. Left side: PCR with β-actin control primers; right side: primers RT-P1A, RT-P1B. 1: water control; 2: PBS injected tissue; 3: rAd-vector injected tissue; 4: rAdHER-Rz injected tissue; 5: rAdHER-mRz injected tissue; 6: rAdHER-As injected tissue; M: molecular weight standard φX-174 digested with HaeIII. (b) Northern blotting for the detection of HER-2/neu mRNA in vivo. Tumor nodules injected with PBS (lane 1) or rAdHER-Rz (lane 2) were obtained 7 days after treatment and poly (A)+ RNA was isolated, Northern blotted and hybridized with HER-2/neu cDNA probe. Expression of GAPDH was used as an internal standard.