US Patent 9005935 Methods and compositions for DNA fragmentation and tagging by transposases

The present invention provides new compositions for transposase-mediated fragmenting and tagging DNA targets. The invention relates to the surprising discovery that use of manganese ions (Mn2+) in transposase reactions improves the transposase reaction. It also relates to the surprising discovery that Mg2+ ions can be used in a transposase reaction with wild-type and/or engineered transposases at levels much higher than previously thought. The invention provides for the use of naturally-occurring transposases in in vitro reactions, as well as improved schemes for cleaving, tagging, and amplifying target DNA.