The MiraZol™ Small RNA Isolation Kit includes MiraZol RNA extraction reagent and other components for enrichment of small RNA from solid tissues and cells. Mirazol is a single-phase reagent that contains guanidinium, a powerful chaotropic agent effective for rapidly inactivating nucleases, and phenol, an organic solvent used to denature and separate proteins and DNA from RNA. The reagent recovers RNAs of approximately 100 bases and smaller, with less than ~5% by mass of contamination with larger RNAs. Solid tissues or cells are disrupted by grinding or vortexing in the MiraZol Reagent. The resulting lysate is mixed with 1-bromo-3-chloropropane (BCP) and centrifuged, which results in phase separation with the RNA partitioned in the upper aqueous phase. The large RNA is then removed by precipitation with low concentration of isopropanol. The supernatant is recovered and mixed with an inert co-precipitant and with additional isopropanol to precipitate the small RNA, which is then recovered by centrifugation. The pellet is washed with 75% ethanol and resuspended in RNase-free water containing a trace amount of EDTA, or in other solvent of choice.