DNA isolation from Dendrobium - (May/07/2007 )

Hi, everyone. I am a fresher. Now, I encouter a problem in my experiment of DNA isolation from Dendrobium, one of Ochid. The DNA was always contamination of polysaccharide. Absorption at 230 nm was high. What is more, the ratio A260/A280 of my sample was more than 2.0, approximately 3.0~4.0. I was confused about how to obtain pure DNA. So I desire for your suggestion, or somebody kindheartedly give me some protocol about DNA isolation from Dendrobium. I heartily appreciate for your help.

-tiny1979-

The usual approach is to use a prep based on CTAB rather than the normal DNA preps. What method are you using?

-phage434-

QUOTE (phage434 @ May 8 2007, 05:38 AM)

The usual approach is to use a prep based on CTAB rather than the normal DNA preps. What method are you using?

Thanks for your reply very much. I used the method of 2%CTAB, together with 20%ethanol to reduce polysaccharide.But the result is not improved.

Hope for your help.

-tiny1979-

Anybody else to give me your hand? I have tried my best to solve DNA contamination , but no obvious effect.

-tiny1979-

Check here:
http://www.arabidopsis.org/comguide/chap_3...B_DNA_extr.html

or use google with "CTAB protocol"

-phage434-

Sincerely thanks for your kindly help.

-tiny1979-

Have you tried to clean up your DNA sample? Add some proteinase K or something like that. or RNase for RNA contamination. Looks more like a RNA contamination to me instead of protein.

-timjim-

QUOTE (timjim @ May 11 2007, 02:38 AM)

Have you tried to clean up your DNA sample? Add some proteinase K or something like that. or RNase for RNA contamination. Looks more like a RNA contamination to me instead of protein.

Thanks for your suggestion. But I have used RNase to digest RNA for 40min at 37℃. I think the high value at A230 looks more like polysaccharide for the DNA solution was usually viscous. Hope for more kindly suggestion for all of you. Thanks!

-tiny1979-