A METHOD FOR THE CHARACTERISATION OF NUCLEIC ACID MOLECULES INVOLVING GENERATION OF EXTENDIBLE UPSTREAM DNA FRAGMENTS RESULTING FROM THE CLEAVAGE OF NUCLEIC ACID AT AN ABASIC SITE

摘要

A method for characterising nucleic acid molecules comprises the steps of: i)introducing a modified base which is a substrate for aDNA glycosylase into a DNA molecule; ii) excising the modified base by meansof said DNA glycosylase so as to generate an abasic site;iii) cleaving the DNA at the abasic site so as to generate an upstream DNAfragment that can be extended; and iv) incubating the extendibleupstream fragment in the presence of an enzyme, for example a polymerase or aligase allowing for extension thereof and a templatenucleic acid and analysing the resultant fragment(s). The invention provides anovel, versatile and simple method using the above-mentionedextendible upstream DNA fragments which allows characterisation of nucleicacids and which has advantages over existing methods. Oneof the most important uses (but not the only use) of the method according tothe invention is to scan or check a fragment of DNA (targetnucleic acid) for the presence or absence of a mutation.