Abstract: The present invention provides methods, compositions, and kits for generating rRNA-depleted samples and for isolating rRNA from samples. In particular, the present invention provides compositions comprising affinity-tagged antisense rRNA molecules corresponding to substantially all of at least one rRNA molecule (e.g., 28S, 26S, 25S, 18S, 5.8S and 5S eukaryotic cytoplasmic rRNA molecules, 12S and 16S eukaryotic mitochondrial rRNA molecules, and 23S, 16S and 5S prokaryotic rRNA molecules) and methods for using such compositions to generate rRNA-depleted samples or to isolate rRNA molecules from samples.