I am going to extract DNA from seawater bacterial. Firstly, I collect the seawater from beach, and then use 0.22 um filters for seawater filtration. I want to extract larger than 10kb DNA-reads from filters. Have anyone used some kits to extract long-sequencing from seawater filters?
Is the ratio of 260/280 about 1.80?
How about the ratio of 260/230?
I would be very appreciated of who attaches results of the gel electrophoresis to this problem.
Thanks a lot!
Hi Ziqi Wu
This protocol works good with water samples, you can try this.....
Method of DNA extraction and application of multiplex polymerase chain reaction to detect toxigenic Vibrio cholerae O1 and O139 from aquatic ecosystems
(2003) Irma N. G. Rivera,Erin K. Lipp,Ana Gil,Nipa Choopun,Anwar Huq,Rita R. Colwell
http://onlinelibrary.wiley.com/enhanced/doi/10.1046/j.1462-2920.2003.00443.x/
at the first the ratio of 260/280 should be 1.80
this link is useful
https://www.ncbi.nlm.nih.gov/pubmed/27712583
regards
Dear Ziqi Wu,
You can use Qiagen or Geneaid DNA extraction kits for extracting large size of DNA fragments. However, both of the kits are quite expensive. Why not trying manual method like CTAB methods.
The ratio of 260/280 is about 1.8 - 2.0. It means that the purity of your nucleic acid is good (1.8 is for purity of DNA while 2.0 is for purity of RNA).
If the value is below 1.8, it means that your nucleic acid samples contaminate with protein, phenol or other contaminants.
The ratio of 260/230 is about 2.0 - 2.2. It is also as secondary measure for the purity of your nucleic acids. Otherwise, the value of the ratio 260/230 usually higher than 260/280.
Here is the link for the kits:
http://www.geneaid.com/products/gel-extraction/gel-extraction-kit-large-dna-fragments
Regards.
Hi Ziqi Wu
This protocol works good with water samples, you can try this.....
Method of DNA extraction and application of multiplex polymerase chain reaction to detect toxigenic Vibrio cholerae O1 and O139 from aquatic ecosystems
(2003) Irma N. G. Rivera,Erin K. Lipp,Ana Gil,Nipa Choopun,Anwar Huq,Rita R. Colwell
http://onlinelibrary.wiley.com/enhanced/doi/10.1046/j.1462-2920.2003.00443.x/
Is not a good idea to extract DNA from any sample fixed in formalin. Specially in seawater samples DNA concentration of the targets are very low and if you add the bad quality produced by the formalin> I seriously recommend to get a least a few samples and fix those in sodium acetate/ ethanol as a positive and degradation control of your protocol. Cheers,
did you try what they did?
http://www.int-res.com/articles/ame/26/a026p013.pdf
- Badges
- Science method