RNA isolation from tissues: RNA pellet is yellow-brown? - Why this? (Jan/20/2006 )

Hello,

another question

I am homogenizing different murine tissues (e.g. thymus, spleen, ear, etc.) for RNA isolation with Trizol.

Some tissues (spleen and ear) result in a yellow or light brown colored RNA pellet after precipitation and ethanol wash step. Where does this color come from? Does it affect the purity of the RNA?

Thanks, Tobias

what do you see with your A260/A280 ratio? I would guess there is something in your pellet that is not RNA...but your spec is the easiest way to see if you have contamination, or perhaps to run a gel