Examples of RNA Isolation Using Guanidinium Salts

RNA from Animal Tissues and Cells Using Guanidinium Thiocyanate 

Freshly dissected soft tissues are cut into small pieces and processed immediately for RNA isolation. Alternatively, the tissue can be flash frozen in 

and RNA STAT-60 (TEL-TEST B, Inc, Friendswood, TX), or similar ready-to-use RNA extraction reagents. It is also possible to isolate RNA, DNA, and proteins simultaneously from the tissue homogenate using guanidine-thiocyanate and phenol [20,21], Since DNA is trapped in the interphase and the phenol phase under acidic pH during extraction, the addition of an equal volume of 1 M Tris solution (pH 10.5) to the phenol phase raises the pH and thereby increases the solubility of the DNA in the aqueous phase. This DNA can be recovered by ethanol precipitation. 

Although guanidine hydrochloride is a potent chaotropic agent, its use for RNA isolation has not been as popular as that of guanidine thiocyanate. The reasons may be that it needs to be used at a much higher concentration to be an effective protein denaturant. The method described here is a modification of methods described in Refs. 15 and 16. 

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