This laboratory manual provides a guide to exploring DNA structure with molecular modeling software from the NCBI. The structures and free modeling software are available in the Exploring DNA structure pack. This text contains several hands-on activities and worksheets to guide your exploration. Chapters are included on the history, discovery, and structure of DNA. Our goal, at Digital World Biology, is to make molecular biology accessible to all. Several hundred students and teachers from universities, community colleges, and high schools, have used the activities in this manual. We hope you agree with our reviewers and find these activities to be an enjoyable way to learn about DNA. Watch a free video tutorial at www.digital-world-biology.com to see how you can use Cn3D to explore DNA.