A method and system for classifying a target nucleic acid includes exposing, in a test system, one or more capture probes to the target nucleic acid. The one or more capture probes is attached to a surface. A first hybridization condition is established in the test system. A first degree of hybridization of the one or more capture probes with the target nucleic acid under the first hybridization condition is determined. A second hybridization condition in the test system is established. A second degree of hybridization of the one or more capture probes with the target nucleic acid under the second hybridization condition is determined and the target nucleic acid is classified by comparing the first and the second degrees of hybridization.