A noncontact stirring method, a noncontact stirring apparatus, a method and apparatus for reacting nucleic acid hybridization using the apparatus, a method for detecting nucleic acid in a sample, an apparatus for detecting nucleic acid, a method for detecting antibodies in a sample, and an apparatus for detecting antibodies in minute droplets 1 .mu.mL or less in an electric field are proposed that can be utilized to speed up biodetection processes, hybridization processes in DNA analysis, ELISA antigen fixing processes, blocking processes, antibody-antigen reaction processes and color reaction processes; and pathogen identification, CRP tests, methods of propagating cells or bacilli such as colon bacilli in a liquid culture medium, and chemical analyses.