Protocol Online logo
Top : Forum Archives: : siRNA, microRNA and RNAi

siRNA extraction from plant material - (May/12/2006 )

Does smallRNAs were precipitate by Ethanol or Isopropanol? Which extraction protocol works good to isolate small RNAs?


tri reagent or trizol work good for siRNA extraction. EtOH and IprOH precipitaes both ethanol if added in enough amount. (1:1 vol per isoprop, 1:2,5 per ethanol (2,5 volumes of ethanol of course))
you may add glycogen or tRNA as carriers.


Is it necessary to keep the sample at -20 C (as for Etof precipitation) when using Isopropanol to precepitate small RNA? Few publications recommend to keep the sample at -20 C for 30 min and others to keep at room temp. for the same span of time to precipitate the RNA. Which is better for iso propanol precepitation?


i incubate them RT when using IprOH. But 30' at -80 when using EtOH.


Can you please explain why do you keep the samples at RT while using IsoOH?


it's related to precipitation capability of the two molecules.
The more C in the molecule, the more precipitation efficiency occurs.

you may have a look at these threads :

dielectricity and ethanol precipiation

iproh etoh and temperature