OnScreen Science announced the immediate availability of OnScreen DNA on Monday. OnScreen DNA is a Universal Binary application that runs natively on PowerPC and Intel-based Macs and lets you visualize and manipulate the structure and workings of DNA in three dimensions. It lets you identify different enzyme components, spin and rotate DNA strands, construct your own double-helix models, and more. OnScreen DNA is available at the OnSreen Science Web site, and is priced at US$199.