Patent ID: 7220543

Claim:
A method for analyzing biological targets of DNA or RNA type, which comprises the following steps: a) contacting the targets to be analyzed with oligonucleotide probes labeled with a cofactor A of an enzyme E, the cofactor being such that it is recognized by enzyme E when it is fixed onto a free oligonucleotide and is less recognized by enzyme E when the oligonucleotide on which it is fixed is hybridized with a complementary oligonucleotide; b) adding, to the reaction medium, enzyme E corresponding to cofactor A and a substrate S of enzyme E, substrate S being converted by enzyme E into a compound C; c) measuring a signal representative of the activity of enzyme E on substrate S; and d) comparing the signal with the signal obtained when the oligonucleotide probes, labeled with cofactor A, are contacted with enzyme E and substrate S, under the same conditions, but in the absence of the targets, the difference between the two signals indicating the presence of complementary targets of the oligonucleotide probes.