total RNA isolation - total RNA isolation (Apr/12/2007 )
Hallo!
I've got a question.
What methods exist to isolate total RNA?
thanks everyone for answer/
The one I used a lot of is RNA STAT-60 from teltest (http://www.isotexdiagnostics.com/rna_stat-60_reagent.html) but I've have a lot of problems with that, but the good thing is that it is really cheap.
Invitrogen makes some really good reagents for total RNA purification from cell cultures, but I've never used it, but I heard from people who use it in neigboring labs and heard good things about it.
-rubyeye
Hello,
Methods for RNA isoaltion depends on the "source" from which you want to isolate RNA.
I am doing RNA extraction from tissue and for that application it is suggested to use Trizol method of Invitrogen.
From where your RNA is coming from? And what are you going to do afterwards with that?
For example i am using RNA for microarray experiment and for microarrays Trizol method is the one suggested.
With the Trizol method you get rid of a lot of proteins, salts and impurities in a high degree. For microarrays you need "extra" clean RNA and Trizol works very well.
Hope i helped. 
Methods for RNA isoaltion depends on the "source" from which you want to isolate RNA.
I am doing RNA extraction from tissue and for that application it is suggested to use Trizol method of Invitrogen.
From where your RNA is coming from? And what are you going to do afterwards with that?
For example i am using RNA for microarray experiment and for microarrays Trizol method is the one suggested.
With the Trizol method you get rid of a lot of proteins, salts and impurities in a high degree. For microarrays you need "extra" clean RNA and Trizol works very well.
Hope i helped.
Thanks. You really helped!
depends of the source and/or the application
I mean if the source is a tissue, i prefer use liquid method (trizol or tri reagent, quiazol seems to be less effective in quality). Moreover for the disruption of the tssue, an homogenizer with small beads is very good. column kits may be suitable for little pieces.
from cells, liquid or columns are ok i think.
Application: if you want to perform analysis regarding small RNAs, you can't use the columns. For ex, the 5S RNA goes in the flow through.
There is a quiagen user-based method for isolation of small RNAs. Briefly, after the first column, you dilute the FT and put it on a 2nd column. Ok it may be efficent, but expensive method i think.
I found recently a RNA modification in a meeting that may be very efficent for RNAs experiences. it's called MRT technology. I don't have financial interest anjd DID NOT TESTED IT MYSELF. So it's for info only
i extract Total RNA using a very typical and old method i think.
i collect mycellia from fungi, grind it under liquid Nitrogen, and add 4M Guanidine Thiocyanate and collect supernatant which i pour in a CsCl column and run it in a ultracentrifuge with 28000 rpm for 24 hours. after that i collect RNA from the bottom of the column and purify it
it takes long time really