Hi there,
I am extracting RNA from environmental samples like soil. I have a three stage protocol. First I use a Chloroform/Phenol based extraction according to Toewe et all, then I am using a Macherey and Nagel Kit and at the end I am using HighPrep Magnetic Beads from Biozyme.
When I measure my sample afterwards on the Nanodrop I get something between 350-800 ng/uL RNA with a 260/280 ratio of 1.93-1.99 and a 260/230 ratio of 1.99-2.18. When I measure the samples on the Qubit I get similar concentrations and if I load the samples onto the Bioanalyzer then I only get one big Peak (not two), so I thought I still might have DNA left in my samples and for further downstresm processing I decided to do a DNA removal.
Therefore, I used the Turbo DNA free Kit, however, after using the kit the quality of my RNA samples dropped according to NanoDrop to 260/280 1.70-1.73 and 260/230 1.80-1.90.
Does anyone of you has an idea why the quality of my RNA decreases after DNA removal and what I could do?
Thank you!