I am experiencing low 260/230 values after using Qiagen's DNeasy PowerSoil Pro Kit. I have been getting values anywhere from around 0.11 to 1.10. After speaking with a Qiagen rep, she recommended that I lower the soil sample to 100 mg of soil, and keep a heated lysis step (heat soil sample plus C1 at 65 °C and vortex every 5 min for a total of 30 min) at the beginning of the protocol, before the PowerLyzer24 step. After trying this, I got a concentration of 23.4 ng/uL, 260/280 was 1.75, and 260/230 was 0.64, so still nowhere near 2.0-2.2. The second sample was 8.6 ng/uL, 260/280 was 1.81, and 260/230 was 0.24. I am not sure why I am having such a high salt concentration.
The rep suggests that I perform an isopropanol precipitation step, but I would like to know what others have done in this instance.
This ratio is used as a secondary measure of nucleic acid purity. The 260/230 values for “pure” nucleic acid are often higher than the
respective 260/280 values. Expected 260/230 values are commonly in the range of 2.0-2.2. If the ratio is appreciably lower than
expected, it may indicate the presence of contaminants which absorb at 230 nm.
Do not worried about 260/280 values too much. Sometimes, it is not precise. I also got a very low value in my simple. But it was still good for running qPCR. What you can do is running in the gel to check it. It may give you some information
Good morning
Sorry I know it's an old post but did you get improvement on your ratio since?
I am doing the same thing as you now and my ratio are the same. Not really good. I want to use the DNA to do NGS so I need it to be a bit better...
Thank you for your help
Kind regards
Elodie Stempien Hello, thank you for your reply. We have not tried retesting these samples, yet. Qiagen, maker of DNA extraction kit, recommended a protocol using isopropanol to yield better values. We are planning on doing this soon. Let me know if you are interested in the protocol and I can share via message.
Hi Vanessa,
I am interested too,. I have the same problem, could you share your protocol?
Thanks
Hi Vanessa Montellano
Thank you for your answer !
Yes If you could share your protocol it would be nice please.
I am trying now with a heated lyse to see if it's better...
Thanks !
- Badges
- Science topic
- Similar topics
- Agricultural Science
- Soil Science
- Soil Analysis