OnScreen DNA Lite as a DNA model on steroids—an interactive virtual model with 35 base pairs. Use it to teach the basic structure, composition, and chemical bonds of DNA. Numerous aids to learning and understanding, including popup labels, an auxiliary linear representation of the model, the ability to rotate the model in space and to toggle between single and double strand views, all within a tutorial framework, make this software fun to play with, which makes the learning "painless." With the help of the on-screen tutorial guides, a student becomes completely at home with the double helix structure of DNA and learns the names of its component molecules and chemical bonds. Of course the base pairing is made clear, but so are the polarity and right-handedness of the DNA strands and what those terms mean. Simulations of the lab phenomena of denaturation and renaturation are also included.