sterile DNA for transfection - (Feb/10/2006 )
How do you prepare sterile DNA for transfection? My maxi-preps are not sterile and thus I see contamination when I transfect.
what kit are you using, you may just need to clean up some around your lab area, what are you resuspending in? make fresh TE buffer for resuspending...
I never used "sterile technique" for maxi-prep just did the prep according to the kit and I never had any problem like this so I think your contamination is coming from something else, especially the buffer you resuspend the DNA in at the end of the protocol...
You may have to get a new kit or replace all the buffers, I would probably replace the buffers and try again with the columns from the kit I had before I went to the trouble of buying a whole new kit (depending on how many columns I had left...)
It may be a good idea to also use an endotoxin free kit, some cells are sensitive to endotoxin
(this wouldn't look like a typical contamination though you just have sick cells, what does your contamination look like?)
Hope that helps...
What does your contamination look like? Dead cells and some debris, because if so it would more be an issue of toxicity instead of contamination.
I've done transfection with miniprep and maxiprep DNA, and never took extra care for working sterila and have had no problem.