I want to extract RNA from cultured treated (with 5-Aza) and untreated cells in order to use for expression array analysis. I have used RNeasy Mini Kit but didn't get good 260/230 ratio (<1), 260/280 ratio was not very good (=1.70) as well.
I am going to use Trizol this time, I found out about TRIzol® Plus RNA Purification System:http://products.invitrogen.com/ivgn/product/12183555?ICID=search-product
Has anyone used this protocol before, I really appreciate any suggestions about this product or any other products or tips which can help me get the pure RNA with good quality.
Is it generally better to freeze down the pellet before extracting at -80 or extract straight away after harvesting the cells?
Thank you very much for your help