Dear Dr. Finkle,

a.)

Very high speed spin, pellet any bugs and pipette from top of tubes...?

b.)

Boil your DNA sample. . .

This will kill any bacterium in it. . .

c.)

Proceed with caution....

I may be fearful the dna's of the contaminant may interfere with my study's as it may be resistant to Chloramphenicol. , and would make new dna preps if possible.

Side Note:

Most DNA preps made are done in open air of the bench due to the fact the plasmid has a resistant marker that will allow you to select it from all others bugs once transformed and plated onto a drug-plate. I have had some problems in the past with some resistant strains of bacterium.

Best Wishes!

Yes it's possible because bacteria can grow in buffer solutions....

It's possible. Luckily for you, DNA is tough.

You can boil it for 10mins then centrifuge it at max speed for 5min in a microcentrifuge, then transfer the supernatant to a new sterile tube. Your DNA should not be impacted enough to alter your experiments.

Boiling and spinning is not going to give you pure DNA...it may be contaminated with bacterial DNA...so make fresh prep and store in -20...with uncontaminated water.....

Hi, if your purpose is sequencing the target DNA, I am afraid boiling might not serve the purpose; it would rather release contaminating bacterium's/bacteria's DNA into your preps.

Did you try plating the PCR water you used? Sometimes, a sloppy labmate can dip a contaminated tip and do not tell others. This can even happen unwittingly. So, I would repeat extraction with a frsh batch of PCR water.

you should evaluate all used stuff. better to use syringe filter instead of boiling

Thank you all for your answers!

I used your advice and performed centrifugation, filtration and boiling in that order on the same DNA and it looks like it cleared the contamination without damaging the plasmid in any way I could observe (it worked well in downstream reactions too).