Total RNA purified with the RNeasy Midi Kit is of high quality and is suitable for many downstream applications. Protocols are also included for cleanup of partially purified RNA, in vitro transcripts, and RNA from enzymatic reactions. An additional buffer is required (composition provided) for isolation of cytoplasmic RNA from eukaryotic cells. Lyticase, zymolase, or glass beads (required for yeast samples) are not provided. Amounts of RNA isolated from samples can vary due to the developmental stage, species, and growth conditions of the sample source. Since the RNeasy procedure enriches for RNA species >200 nt, RNA yield does not include 5S rRNA, tRNAs, or other low-molecular-weight RNAs.