Patent ID: 8029993

Claim:
A method of producing an asymmetrically tagged nucleic acid fragment, said method comprising: i) ligating an adapter to both ends of a double-stranded nucleic acid fragment, wherein said adapter comprises: (a) a first and a second nucleic acid strand hybridized together, wherein said hybridized strands comprise one or more wobble base pair; (b) a ligation site positioned on a first end of said hybridized strands configured to allow ligation of said adapter to said double stranded nucleic acid fragment; and (d) a nucleic acid synthesis primer binding site positioned upstream of said one or more wobble base pair; ii) annealing a synthesis primer specific for said nucleic acid synthesis primer binding site to said adaptor ligated fragment; and iii) performing a first round of nucleic acid synthesis initiated from said annealed synthesis primer, wherein the nucleotide base incorporated at said one or more wobble base pair in the adapter region at a first end of said adaptor ligated fragment is different than the corresponding nucleotide in the adapter region at a second end of said adapter ligated fragment, thereby producing an asymmetrically tagged nucleic acid fragment.