RNA extraction 260/230 ratio - (Sep/16/2009 )

Hi there,
Greeting, I'm using Rneasy RNA QIAGEN, I always get good concentration and good 260/280 ratio but the problem is I have low 260/230 ratio, at the beginning i got around 0.3 but i was able to increase it to 1.5, still low, i'd like to have it in the range of 1.9-2.1. as required for microarray.
I guess this is related to EtoH, however, i dried the sample but same problem occurs.
Does anyone can help with more suggestion.

Thank you in advance
Best regards
Salem

-Salem-

Salem on Sep 16 2009, 10:02 PM said:

There are a lot of reagents and sample components that absorbe in UV range. Try this:
- Try to help protein precipitation by heating to 70ºC (dry bath).
- After protein precipitation, don't try to aspirate to the last drop of supernant. Try to disturb the pellet as low as posible.
- Before RNA elution, spin your empty columns to remove any rest of washing buffer

I hope it helps you

-LabDiagMol-

Thanks for your reply
I'll try it and let you know

-Salem-

I tried what you said but the 260/230 ratio still low
Any other suggestion

Thank you

-Salem-

Hi Salem,

Has your problem resolved?

If not, perhaps you can browse this link http://answers.yahoo.com/question/index?qi...26155235AAi9J1h and hopefully your problem can be solved.

P.S. Please tell me how you feel about this link, thanks a lot.

-stylothecancer-

Hi stylothecancer,
Actually I found this link too and i was going to try it.
I'll let you know tomorrow
Anyway thank you very much

-Salem-

Hi stylothecancer,
Thank you for the link, it's really helpful, i did the extraction today and i got good results 2.0-2.1
Also, i did some steps including:-
Fliping the column to wash it.
1 more wash with RW1.
Followed with 80% ethanol washing.
Elute the elute.

Anyway thank you stylothecancer and labdiagmol for the help

-Salem-