Blunting and Ligation Kit: Our kit is based on the polymerase activity of the Klenow DNA Polymerase that allows the filling-in of incompatible recessed 3'-termini. For the restriction fragments obtained after digestion with two different endonucleases it is possible to repair only one end selectively. This is performed by cleaving DNA with the restriction enzyme I, filling-in the ends with Klenow DNA Polymerase of E. coli DNA polymerase I, heat inactivation of polymerase at 75o C for 10min prior to digestion with the restriction enzyme II. Cleavage with the enzyme II can be done in the same reaction buffer if buffers for both restriction enzymes are compatible.