RNA re-extraction with phenol - I can't get a good RNA quality (Feb/09/2007 )

Hi there!

I have extracted some RNA with phenol (Trizol) from lymphocytes, in order to do a microarray assay. However, some of my samples presented a bad 260/230 ratio. So, I have re-extracted the RNA from these samples, starting from the phenol step and what I´ve got were similiar ratios.
Does someone could tell me what might be the problem? Is there another more efficient method to make it?
Please.

Doda.

260/280 or 260/280 ratio?
By the way, over dry RNA pellet could not dissovle in water properly and might result in low 260/280 ratio

a bad 260/230 ratio may indicate phenol contamination. re-extract with chloroform or chloroform/iaa.

Doda,

you can tranfer the aqueuoeus (? how is that spelled) phase into a new tube, mix it with ethanol an directly load it on an RNeasy column ...