guanidine life span

Pierre Jelenc pcj1 at
Wed Dec 2 18:06:07 EST 1992

In article <1fhnqsINN41v at> andrewh at (Andrew Hobbs) writes:
>Loryn Sellner (loryn at wrote:
>: I have just recently started using a guanidine thiocyanate extraction method 
>: for extracting viral RNA. I want to know how long the extraction solution 
>: can be stored for and under what conditions (i.e. frozen, at 4 C, etc.).
>: Any information from other people using this method would be greatly 
>: appreciated. The extraction solution contains 8M guanidine isothiocyanate, 
>: 50mM Na citrate, 100 mM 2-ME, 1% sarkosyl, 1 ug/ml yeast tRNA.
>: Ta.
>: Loryn Sellner
>: Department of Microbiology
>I have used the guanidinium (iso)thiocyanate solution up to 3-4 months
>after making up and storage at room temperature, as long as the 2-ME is
>omitted.  I normally add 2-ME just before use to just sufficient
>solution.  I'm not sure I would keep it for more than a few days with
>the 2-ME included.

There is no such thing as "guanidine ISOthiocyanate". All ionic compounds
of this type are THIOCYANATES, labels on several popular sources of the
stuff notwithstanding. The only isothiocyanates are covalent compounds
where the sulfur is bonded to carbon.

Pierre Jelenc                        pcj1 at 
                                    Columbia University, New York

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