turbid DNA from maxiprep - (Oct/02/2011 )

hi everyone,
i got a very weird DNA product from Maxi prep,
i used the Nucleobond Xtra EF maxi kit, and after precipitation with isopropanol and washed with 70perc etOH,
i got a very white DNA pellet, after drying it turns transparent but still slightly white.
i dissolved in nuclease water and checked the ratio is very good, 1.87 at 260/280 and 2.2 at 260/230, however,
the dna looks a bit milky and turbid, not very clear and transparent look like water ( which i usually got with qiagen kit), i was wondering what would be the possbile reasons for this, as it doesnt seems like contaminated by protein. can i transfect cells with this kind of milky plasmid? can anyone has the same experience like this, appreciate for any help

thanks

Dan

are you sure the pellet is dissolved completely?
...if you centrifuge the solution there is no precipitate?

Regards,
p

hi, thanks for your suggestion

i did the spinning, and it got a very viscous pellet, the supernatant is still keeping the same concentration of the dna,
but i am still wondering what would that be so that i could avoid this issue next time. is the pellet SDS?

thanks

dan

seems like the DNA pellet was not dissolved totally ...when the pellet has been overdried it is often hard to dissolve it completley.

You can try incubating at moderate temperature 37°-50°C with slow shaking ...or do some freezze-thaw cyles ...this helps most of the time. You can check if the DNA concentration increases with time.

Regards,
p