mantei at cell.biol.ethz.ch
Sun Oct 31 12:53:14 EST 2004
In article <cm31c4$mb4$1 at news5.jaring.my>,
"BoonChoon" <boch19 at pd.jaring.my> wrote:
>I'm doing colony hybridize (E.coli) follow by Southern Blot, my colony
>hybridize seem giving me high background signal (perhaps because of the
>E.coli protein), all colony give positive signal. Anyone can help me???
If your probe was prepared by cutting a fragment out of a plasmid
vector, you might still have some of the vector in your fragment
preparation. If you label and hybridize this to colonies containing the
plasmic, all will react.
This can be avoided by using PCR to prepare the probe fragment. Start
with about 1 pg of plasmid as template, so that the amount of vector
backbone present in your product will be negligible.
Department of Cell Biology, Swiss Federal Institute of Technology
CH-8093 Zurich, Switzerland
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