Patent ID: 6867001
Filing Date: 2005-03-15
Classification: C12N,C40B

Abstract:
1. A method of constructing a circular DNA library having increased proportion of a first double-stranded DNA by removing from an original circular DNA library, a second double-stranded DNA that is not identical to the first double-stranded DNA, said method comprising the following steps: (1) linearizing circular DNA in an original circular DNA library comprising a first double-stranded DNA and a second double-stranded DNA to form a linear DNA library; (2) preparing single-stranded DNA corresponding to the second double-stranded DNA; (3) adding RecA protein and the single-stranded DNA to the linear DNA library to produce a mixture, wherein the mixture comprises linear first double-stranded DNA and triplexed DNA, and wherein the triplexed DNA is formed through the binding of the second double-stranded DNA and the single-stranded DNA prepared in step (2) via the RecA protein; (4) subjecting the mixture formed in step (3) to self-ligation to selectively circularize double-stranded DNA that dose not contain a triplex; and (5) removing noncircular DNA from the ligated mixture formed in step (4) to produce a circular DNA library having increased proportion of the first double-stranded DNA in comparison to the original DNA library.