plasmid question

[Andrea Galli]

Just guessing, my first thought was an insertion problem. Maybe the
mutation happened in/near the replication region and affected also one
restriction site, thus causing the "elongation" of the previous short
fragment.

You should give some more info:
	what kind of plasmid is it ?
	where it is mantained ?
	what sites does it contains (e.g. polilinker, ori-c, boxes, etc) ?

SeeYa, Andrea Galli


> I have a  plasmid about 2.8kd which is easily handled several months
> ago. But now it has gone wrong. The problems are as follows:
> 
> 1. It replicates poorly now.
> 2.The result of single enzyme digestion is not complete any more.
> 3. When I use two enzymes to digest it, I can't see the small fragment I
> want any longer. Moreover the relatively large fragment is not only one.
> 
> What's the matter? I have been trapted in it many days. I really got
> headache on it.