UltraPure™ Guanidine Hydrochloride is a strong protein denaturant. In a highly concentrated (5 to 6 M) guanidine hydrochloride solution, many proteins unfold and separate into their constituent polypeptide chains. Guanidine hydrochloride is widely used to purify nucleic acids from cell extracts. It is useful as an RNase inhibitor during the isolation of mRNA from mammalian cells.