In a previous article, nelleman at biobase.aau.dk (Lars Nellemann) wrote:
>Guanidin-thiocyanat acid phenol vs. CsCl centrifugation in RNA
>Has anyone observed that large or small transcripts are selectively
>removed by using one of these methods.
>I have observed, that small RNAs as tRNA are removed during CsCl
>centrifugation, but not when using the guanidin thiocyanat-acid phenol
>Has anyone observed the same, and is it possible that the reverse
>is possible, that very large RNAs are removed during acid-phenol but not
>in CsCl centrifugation.
>Please reply at:
>nelleman at biobase.aau.dk ----
I've not observed this (removing large RNAs) with the acid phenol. We have
used the protocol (Chomczynski & Sacchi) all the time for tissue culture
cells and have sucessfully conducted Northerns for Complement components C5
and C3 both of which are 5-5.5 kb in length. I have found a difference
bewteen water saturated phenol and tris phenol, that being less of an RNA
yeild with the tris phenol.
Hope that helps,
haviland at kids.wustl.edu