Factor VIII mRNA levels in the liver pre- and post-vWF infusion. Total RNA was isolated from samples of porcine liver biopsied pre- and post-vWF infusion. The total RNA samples (10 and 15 mg) were assayed by RNAse protection as described in Materials and Methods (Panel A). Analysis of a 1/50 aliquot of the probe (lane 1) showed that under these assay conditions the radiolabeled probe was in vast excess. Densitometry of the autoradiogram indicated that levels of factor VIII mRNA did not significantly differ between pre-vWF infusion (relative band intensities were: 1.0 U/10 mg RNA and 1.8 U/15 mg RNA) and post-vWF infusion (1.1 U/10 mg RNA and 2.0 U/15 mg RNA). The amount of poly(A)⁺ RNA was determined by dot-blot hybridization to a poly(T) probe (panel B). For controls total CHO cell RNA and yeast tRNA were analyzed as indicated. Densitometry of the dot-blot showed that pre- (area = 4.5) and post-vWF (area = 4.8) infusion samples did not significantly differ in their hybridization to the poly(T) probe.