Ghosts seen in plasmid preps

[Paul N Hengen]

| Sometimes, after DNA isolation from agarose gel, I see a band appearing
| at a lower MW.  I wonder what is the nature of that band (I suppose it
| is a denaturated form) and how I can avoid this problem.
|
| Thank you very much
|
| Daniel

If you are using pBluescript or a pUC derivative, you might be seeing what
is referred to as "Freddy". It is a common problem. See this article for
more information:

@article{Hengen1994Martibs,
author = "P. N. Hengen",
title = "Methods and reagents - Ghost plasmid of pBluescript",
journal = "Trends in Biochemical Sciences",
volume = "19",
number = "3",
pages = "139-140",
month = "mar",
year = "1994"}

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