This lively, informative, colorful Web site comes from Quill Graphics, a source of scientific images and animation for many television shows. Compare the size of a human sperm to that of a bacterium or virus. Watch how HIV infects a cell and reproduces inside it. Follow immune cells as they react to the presence of a bacterium—or a splinter. Learn how dust mites cause an itch. Or simply enjoy the gallery of pictures documenting the microscopic realm we so often ignore.

Go to: http://www.cellsalive.com/index.htm