MaxiPrep low plazmid concentration - (Aug/29/2007 )

Hi everyone,
I am a freshman here, I hope somebody could help me. I just did Maxi Prep and my plasmid concentration is really low (0.3ug/ul). How could I increase the concentration of my plasmid?
Thanks in advance
Sofia

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The easiest method would be to ethanol percipitate your plasmid DNA and resuspend it in a smaller volume.

1. Add 1/10 volume of 3M sodium acetate
2. Add 3x volume 100% ethanol
3. Spin down at maximum speed in a centrifuge for 10min
4. Discard supernatant
5. Wash pellet with 70% ethanol
6. Discard ethanol wash
6. Leave tube to dry a little
7. Resuspend DNA pellet in a smaller volume

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Thanks a lot for the quick reply. My plazmid is diluted in TE. How 3M sodium acetate will react with TE?

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Is 300ng/ul a really low plasmid concentration? Seems a reasonable concentration to me (unless you have eluted/resuspended in a very low volume of TE). It's not a fantastic yield, but it should be sufficient for most applications...

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Thanks a lot for the replay. Is this concentration is OK for doing Calcium phosphate transfection ? I know that TE and calcium fosphate don't get along together, TE somehow eliminate calcium phosphate effect.
Thanks again

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then why didn't you resuspend that plasmid just in tris 10mM ? you could have save a part of it as stock and use the rest for transfection...

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EDTA in TE quelates calcium, so transfection does not work.
As i recall from my transfections 0.3ug/ul should be high concentration enough, i used to do minipreps and not bother with maxis. also, always resuspend just in ultra pure water as this wont interfere with any downstream applications.
good luck!

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