Abstract: Provided is a method for identifying a functional antisense agent, which method comprises hybridizing an RNA with an aligonucleotide probe and measuring in real time the kinetics of hybridization, wherein the kinetics are measured by either hybridizing in the presence of an intercalation dye and recording a change in the spectroscopic properties of the dye as hybridizing proceeds, or incorporating a label in either the RNA or the probe, attaching the non-labelled RNA or non-labelled probe to a solid support, generating an evanescent wave in the proximity of the non-labelled RNA or non-labelled probe and recording the increase in a signal generated by interaction of the evanescent wave with the label, as hybridization proceeds.