Patent ID: 7153652

Claim:
A method of identifiably detecting a mismatch in any of a plurality of DNA duplexes of distinct nucleic acid sequence, comprising: phenotypically sorting from said plurality of distinct duplexes those that initiate a mismatch corepair event in a bacterial cell, to form a phenotypically sorted population, wherein such mismatch repair event takes place only when there are together in a polynucleotide within the bacterial cell (i) a distinct duplex having a mismatch of from 1 to 4 contiguous nucleotides in length, and (ii) an inactive marker having a mismatch of at least 5 nucleotides in length that does not activate the methyl-directed mismatch repair system of the bacterial cell, and wherein such marker is repaired to generate a distinguishable cellular phenotype; and then identifying the duplexes present in said phenotypically sorted population, wherein identification is effected by identifying at least one genotypically detectable genetic element uniquely linked to each said phenotypically sorted duplex.