Method for Fragmenting DNA by Nick Translation

A composition comprising:

• i. one or more enzymes capable of nick translating activity;
• ii. a dNTP mix comprising a dNTP having a modified base;
• and
• iii. at least one modification-sensitive nicking endonuclease that is prevented from nicking DNA if its recognition site contains the modified base.

A method for fragmenting DNA comprising:

• (a) combining in a reaction mix:
• i. one or more polymerases capable of nick translating activity;
• ii. a dNTP mix comprising at least one dNTP having a modified base;
• iii. at least one modification-sensitive nicking endonuclease that is prevented from nicking DNA if its recognition site contains a modified nucleotide;
• and
• iv. a sample comprising a double-stranded DNA template that comprises recognition sites for the at least one modification-sensitive nicking endonuclease;
• and
• (b) incubating the reaction mix for a period of time in order to produce fragments of the double-stranded DNA template, wherein the fragments comprise the at least one modified base.