Ashok Aiyar aiyar at
Fri May 16 09:17:16 EST 1997

[Posted and mailed]

In article <199705151728.NAA03003 at>,
	dalex at NEXUS.MICROIMM.MCGILL.CA writes:
> Hello!
> I have constructed a transcriptional lac fusion on a
> high copy, ColE1-based vector.  This fusion was supposed
> to allow me to monitor transcriptional regulation of my gene.
> Unfortunately,  the high copy number appears to be interfering
> with regulation.   I would like to know if it possible to use this
> construct to create a chromosomal fusion.

There are two simple ways to do this.
a) clone your cassette into a low copy number vector - i.e. one
   which is maintained at one to two copies per cell, or
b) clone your cassette into lambda and make a lysogen

The latter more or less ensures that your cassette will be at a
single copy.

Ashok Aiyar, Ph.D.
McArdle Laboratory for Cancer Research
aiyar at

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