Methods for detecting target nucleic acid sequences

A method for the detection of a target nucleic acid, which method comprises:

• (a) bringing together in a nucleic acid hybridization medium (i) nucleic acid from a sample, said nucleic acid comprising a template nucleic acid sequence and a target nucleic acid sequence, and (ii) a tailed nucleic acid primer comprising, in 5′ to 3′ order, a template binding region and a tail comprising a linker and a target binding region, in the presence of appropriate nucleoside triphosphates and an agent for polymerization thereof, under conditions such that the template binding region of the primer will hybridize to a complementary sequence in the template nucleic acid and be extended to form a primer extension product, the tail of the nucleic acid primer remaining uncopied during amplification, and
• (b) separating any said product from the template, whereupon the target binding region in the tail of the primer will hybridize to a sequence in the primer extension product complementary to the target nucleic acid, and wherein any such target specific hybridization is detected via a detectable change in a signalling system, such that the presence or absence of the target nucleic acid in the sample is detected by reference to the presence or absence of a detectable change in the signalling system.