Short nucleic acids such as microRNAs are way too short to be targeted by two conventional primers required for PCR. Current methods therefore extend short nucleic acid targets by some means prior to amplification. This, however, compromises the sensitivity and the specificity of the assay. TATAA has found a solution. In Two-Tailed PCR a single molecule, designed with a hair-pin structure, hybridizes with both its termini, referred to as hemiprobes, to the target. Each hemiprobe alone is too short to bind but being part of the same molecule binding is cooperative and their combined affinity is sufficient. This leads to greater sensitivity but also superior specificity as sequence variation has much greater impact in the short hemiprobe binding region.