RNase Treatment: Samples (~0.5 µg RNA) were mixed with 0.85 µg of RNase A (NEB) diluted in PBS and incubated at 37˚C for 2 hours. Samples were centrifuged at 16,000 x g for 5 min and the supernatant was removed and then washed with 1x PBS. One sample at a time, 10 µL of RNA loading dye was added to each MOF-containing sample then 10 µL of 100 mM EDTA was immediately added with 4 µL of heparin sulfate (25 mg mL -1 ). Samples were heated to 60˚C for 10 min. Samples were run on a native, Sybersafe, 1% agarose gel at 80V for 40 minutes. The gel image was obtained using a Bio-Rad ChemiDock imager.