Almost all living organisms, including plants, fungi, insects, and humans, have DNA. Variation in DNA, or genetic variation, is responsible for most of the diversity one sees in nature. By analyzing DNA, it is possible to create a DNA fingerprint that is unique to an organism. DNA fingerprinting is used in several disciplines of science, including forensics, the study of disease transmission, the production of biofuels, and the study of biodiversity. DNA fingerprints can be created by using restriction enzymes and gel electrophoresis. As biology graduate students working in middle school science classrooms, the authors are always trying to find creative ways to help students understand science and incorporate research practices. Simulations expose students to research methods even if a certain technology--in this case, the technology required to conduct gel electrophoresis--is unavailable. In this paper, the authors review DNA fingerprinting and describe two standards-based lessons they have used in middle school science classes to provide a hands-on approach to learning the basic idea of how restriction enzymes work, the fundamentals of gel electrophoresis, and the resulting DNA fingerprint. (Contains 6 figures and an activity worksheet.)