Isolating RNA without using DNase??

[Hiranya Roychowdhury]

At 02:16 PM 11/8/96 GMT, Edouard Lauzier wrote:
>In article (Dans l'article) <55u4sh$d4h at news.iastate.edu>,
>qfdong at iastate.edu (Qunfeng Dong) wrote (=E9crivait)=A0:
>
>> Hi, there:
>>=20
>>   When I read the "current protocols in molecular biology", I am curious=
 why
>> those RNA isolation procedures don't need to use DNase in any step, how=
 is
>> DNA removed during the isolation??
>>=20
>> Qunfeng
>> --=20
>> Qunfeng Dong
>> qfdong at iastate.edu
>
>The phenolic phase of your mixture is bring to acidic pH ( <8.0 ) wich
>cause DNA and not RNA to partitioned in the organic phase wich you do not
>take of course...
>
>Hope it helps ( and correct me if I'm wrong people !)
>
>Bye...
>--=20
>Edouard Lauzier, B.Sc.                           elauzier at fse.ulaval.ca
>Physical Activity Science Laboratory       (418) 656-2131 #2929
>(Laval University)  G1K 7P4
>CANADA
>
>


Edouard,
The phenol used in routine RNA extraction is buffered >pH7.5. At this pH,
neither DNA nor RNA will be partitioned with the organic phase. The DNA in
such preps is removed by differential pptn. of RNA in 2M LiCl.



>
Dr. Hiranya Sankar Roychowdhury
Plant Genetic Engineering Lab.
New Mexico State University
Las Cruces, NM 88003
Ph. (505) 646-5785
hroychow at nmsu.edu