Patent ID: 6406847
Filing Date: 2002-06-18
Classification: C12Q

Abstract:
A method of detecting a mismatch between two substantially complementary DNA sequences of interest, the method comprising:annealing and ligating a single reaction comprising: first vector strands lacking methyl adenine, wherein each vector comprises one of a plurality of distinct sequences of interest, a gene encoding a detectable marker, and an origin of replication active in a bacterial host cell; a second vector strand substantially complementary to said first vector and characterized by the presence of methyl adenine at GATC sites, wherein said gene encoding said detectable marker further comprises an inactivating insertion, deletion or substitution of at least 5 nt; and a test sequence substantially complementary to said sequence of interest, and suspected of having at least one mismatch of from 1 to 4 contiguous nucleotides in length; transforming a bacterial host having an active methyl mismatch repair system with the product of said ligating step; determining the presence of bacterial transformants expressing or not expressing said detectable marker; wherein the presence of transformants not expressing said detectable marker is indicative of a mismatch between said sequence of interest and said test sequence.