DNA isolation - (Jun/27/2013 )

Hello all,

I was discussing the issue related to isolating the Bacterial DNA from a particular vegetable samples. However, I understand that if I do use the sample (vegetable) I will end up having DNA's of the plant itself.

I am totally new in this area as well. What is the best way to isolate Bacterial DNA when am not interested for example in molds and other species DNA???

Thanks in advance for your answer

The best way would be to cultivate the bacteria so that you have a pure culture and then do the DNA extraction. Failing that, you could separate the bacteria from the plant by washing and density gradient centrifugation to separate from yeasts and other fungi, then DNA extract.

Thank you ! so bacteria on surfaces are washed (having to go for the option of washing) , these are the bac on the surfaces of the plant. But for potentially internalized bacteria (within the tissue) seems not logical? I mean I could cultivate the bacteria, but supposedly there would be uncultivated ones how to do that?

No idea sorry, I'm a virologist not a bacteriologist. If you just want to characterize the species, say by 16s RNA gene identification, then you don't really need to worry about the plant DNA as this shouldn't have the 16s genes. Other than the bacteria being a very low proportion of the total DNA isolated there won't be much problem with this approach.

Thank you!! that was helpful!