do you always see three bands on your miniprep? - (Oct/14/2005 )
Dear, since I saw most people talked about three bands on your undigest plasmids. My miniprep was using QIAGEN kit and I did not always see three bands faithfully. I only saw one band around the size of the plasmids. Is it that happening to you?
My digestion not work, I am kind of concerning about everything. so do not laugh.
You should see 3 bands, one containing CCC DNA (covalently closed circular DNA), one with linear DNA (a small part of your DNA is cut somehow) and one with nicked DNA. They migrate in this order if I'm not mistaken. The CCC DNA should be the most clear one, if that one is hardly visible, you probably didn't load enough DNA to visualise the other two.
If you are only seeing one band, and it is running as linear, then it's likely it is linear plasmid. You're not vortexing your minipreps, are you?
not at all