plating from chlor onto amp

[Frederik Wirtz-Peitz]

Dear all,

I am trying to clone an insert which contains a chloramphenicol marker into
a vector which features an ampicillin marker. I plated my ligation onto
chlor plates, then streaked out individual colonies on an amp plate, from
which I picked colonies for mini-prep. I am now worried that, since chlor
isn't lethal but only inhibits growth, there may be significant background
of re-circularized vector on the amp plates (defeating the purpose of
plating on chlor in the first place). Does anyone know if this is a valid
concern? (I only just set up the mini-preps so I don't know the result yet.)

Thanks.