We have developed a new DNA extraction experiment for high schools. It uses the concept “Life possesses not only unity, but also diversity” to teach Japanese and American students that various organisms have DNA in their bodies as a common chemical background. In this experiment, students extract DNA from representative organisms of the five kingdoms Monera, Protista, Fungi, Plantae, and Animalia (although the system of classification into five kingdoms has been replaced by three domains in current taxonomy, Japanese students are familiar with this classification system from their earlier education). After practice experiments with high school students and biology teachers were performed, the educational effects were evaluated by questionnaires. The results suggested that the DNA extraction experiments were effective to a certain extent and that, although several points should be improved, this experiment is adequate for practice in high schools.