“…Seamless cloning methods generally rely on short (~15 bp) end homology regions for ligation of insert and vector DNA fragments. These methods are available through commercial kits, which are widely used [4] , [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] , [13] , [14] ; however, seamless cloning kits are cost-prohibitive. Recently, several simple and recombinant enzyme-free seamless DNA cloning methods have been described [15] , [16] , [17] , [18] , which utilize the endogenous homologous recombination activity of laboratory Escherichia coli strains.…”