Ethanol precipitation of RNA and the use of carriers

Recovery of deproteinized RNA almost always is performed via precipitation with ethanol. If the RNA is free of contaminants (i.e., it is well extracted) as determined by spectrophotometry, it will resuspend easily and be ready for any subsequent manipulation. Ethanol precipitation is quite useful because it provides quantitative recovery of any-sized RNA, from several kilobases to 20 nucleotides (nt). Major considerations in this protocol are RNA concentration, pellet identification, and resuspension.