The DNA extracted by kit contain only nucleus DNA?

[bbsinfo]

Hey, I am very new, please bare with my stupid question. Does the DNA extracted by extraction kit contain only nuclear DNA? Or it also contain organalle DNA, such as mitochondrial DNA and plasmid DNA?
Thanks

[tonybolger]

Hey, I am very new, please bare with my stupid question. Does the DNA extracted by extraction kit contain only nucleus DNA? Or it also contain organalle DNA, such as mitochondrial DNA and plasmid DNA?

Not that i've used kits, but given the major pain that organelle DNA usually is, you're unlikely to get rid of it without major effort - selective lysing, centrifuge gradients etc.

Even then, you're talking "enriched for nuclear DNA" rather than "pure nuclear DNA".

Plant DNA extraction, depending on the species, also has to deal with a lot of secondary metabolites, which can require quite a brew of counter-measures in the buffers.

[biznatch]

I think it depends on the kit. Unless the kit specifies nuclear DNA you're probably getting everything. I do lots of RNA extraction and that is the case. I have to add extra steps to get just nuclear RNA.

[bbsinfo]

you're unlikely to get rid of it without major effort - selective lysing, centrifuge gradients etc.

You have to do extra selective lysing or centrifuge before you perticipate your DNA pallets, am I right? Many thanks!

[bbsinfo]

And I also have another confusion. I realized that some people believe that if you mention "genomic DNA" that only means nuclear DNA. But I have read paper, in which people use "genomic DNA" to refer both nuclear DNA, and organelle DNA.
So what is more precise? Thanks

[yaximik]

The vast majority of kits designed to isolate just double stranded DNA, which means any kind of dsDNA. Because mtDNA present in larger molar amounts per cell, you get more copies of mtDNA.