Method for hybridizing nucleic acids and hybridization apparatus

A method for hybridizing a target nucleic acid and a probe nucleic acid that can specifically bind to the target nucleic acid and that is immobilized on a substrate by circulating a sample solution containing the target nucleic acid, comprising:

• a reaction step of allowing the target nucleic acid contained in the sample solution to react with the probe nucleic acid, wherein the reaction step is performed in a first region;
• a recovery step of recovering the sample solution after the reaction step;
• a heating step of heating the recovered sample solution to the denaturation temperature of the target nucleic acid or a higher temperature;
• an adjustment step of adjusting a temperature of the heated sample solution to an optimum temperature for hybridization, wherein the adjustment step is performed in a second region different from the first region, and the temperature of the heated sample solution is adjusted directly from the temperature obtained in the heating step;
• and
• a supplying step of supplying the sample solution containing the target nucleic acid in a denatured state resulting from the adjustment step to the first region to react with the probe nucleic acid,
• wherein the sample solution comprises a single-stranded nucleic acid complementary to the target nucleic acid, and
• wherein the flow rate for supplying the probe nucleic acid with the sample solution is set so as to satisfy the following relationship:
• the time required for the sample solution whose temperature is controlled to the hybridization temperature to reach the probe nucleic acid < the time required for the number of single-stranded target nucleic acid molecules in the sample solution to decrease by half.