That's how I would do it.

I had used Trizol and I recommend to do it

Thanks. Ahmed would you share your protocol with me? I find a little confusing the ones I've read.

Hi Juarez,

Trizol is working good for DNA & RNA from the same sample, but quantity and quality of RNA is depended on the initial quantity of cells. If possible take 70% confluent 10 cm plates as starting material, it will give good result. My experient is with adherent culture. You can use some commercial kit (eg. Qiagen) for same but if you required small RNA than be careful while selecting kit, however trizol isolates all RNAs.

Esmeralda Juarez ,,, here is my protocol and the purity of RNA was good.

Good Luck

You may find one of these zymokits useful:

http://www.zymoresearch.com/rna/total-rna-purification/dna-rna-co-purification/zr-duet-dna-rna-miniprep

http://www.zymoresearch.com/rna/total-rna-purification/dna-rna-co-purification/zr-viral-dna-rna-kit

Good luck!

Thank you all. You've been very helpful. I won't start from zero.