How is RNA isolated?

RNA extraction is the purification of RNA from biological samples. Several methods are used in molecular biology to isolate RNA from samples, including guanidinium thiocyanate-phenol-chloroform extraction, glass fiber filters based on silica technology, magnetic beads assisted purification, as well as column chromatography. Among these methods, guanidinium thiocyanate-phenol-chloroform extraction, using commercially available TRIzol (TRI reagent), is the most common one, which isolates RNA from DNA and proteins based on their different solubilities in aqueous and organic solutions.