eosophageal cells

[John Fox]

In article <alan.1.001DE799 at gecko.biol.wits.ac.za>, alan at gecko.biol.wits.ac.za (Alan Thornley) says:
>
>We are trying to transfect a line of eosophageal carcinoma keratinocytes with 
>an inducible expression vector (pMSG-Cat). At present we are having a lot of 
>trouble with maintenance of the plasmid in the cells. Does anybody have any 
>ideas???

Could you specify the problems that you are encountering please?