If the recognition site is preceded by GA and followed by TC, or constitutes a CCWGG sequence (methylation site), you may not be able to digest the plasmid. Hence, it is recommended to avoid enzymes such as: XbaI (TCTAGA), ClaI (ATCGAT), ApaI (GGGCCC), AvaII (GGWCC), SfiI (GGCCNNNNNGGCC), StuI (AGGCCT). However, if you are unable to avoid using these enzymes on the methylated cloning sites for your plasmid, you may use a dam deficient strain such as GM2163 (E4105S), ER2925 or JM110 to amplify the DNA before digestion. Please inform us while placing the order.