RNase Protection Assays for Quantitation of Gene Expression in Vascular Tissue

Ribonuclease protection assay (RPA) is a sensitive solution hybridization method for quantitation of specific RNAs (1 –3 ). The method is based on the ability of single-strand specific ribonuclease to degrade single-stranded RNA while leaving intact fragments of labeled antisense RNA probe, which are annealed to homologous sequence in the sample RNA. After ribonuclease digestion, the hybridized portion of the probe (“protected fragment”) can be visualized via electrophoresis of the mixture on a denaturing polyacrylamide gel followed by autoradiography.