restriction site lost in DH5-alpha

[Xin Guo]

Hi, everyone:

I purified pCAT from JM101. We have made an insert in this pCAT
between Hind III and Pst I sites. The restriction enzyme digestion
and sequancing also show right insertion. After transformed DH5-alpha
cells, pCAT lost Pst I site. Is this a usual result? How do you make
sure you get the right colonies after transformation (with amp+ 
resistance)? 

Xin        vp23qw83 at ubvms.cc.buffalo.edu