Replica plating: transfer of the colonies from one plate to another using absorbent pad or velvet($1p) transfer of colonies +ampicillin ampicillin tetracycline these colonies have bacteria with recombinant plasmidReplica plating: transfer of the colonies from one plate to another using absorbent pad or Velvet (绒布). transfer of colonies +ampicillin + ampicillin + tetracycline these colonies have bacteria with recombinant plasmid