This website has 3 auto-tutorial case studies that ask students to analyze and interpret microscopic images. One case study (Battle of the Biofilms) involves using fluorescent antibodies to determine how to best treat a Legionella biofilm on a cruise ship. In another (Cryptosporidium and the New York City watershed), the student must decide whether or not New York City should filter its drinking water. Another (The Fatal Flu) asks students to solve an outbreak mystery using information from Gram stains, fluorescent microscopy, and transmission electron micrographs. Worksheets are provided online, and each case requires the student to write a summary essay with a recommendation for action, based on the situation.