This lesson is a summary of a mini-unit put together by myself and five other St. Louis area teachers during a summer internship in immunology. This lesson is designed to serve as an introduction to the immune system. It can stand alone or it can lead into further studies of the immune system. After focusing the students' attention on allergic reactions, two hands-on experiments allow students to explore the specific reaction between an antigen and the antibody that recognizes it.
Students carry out an exploratory experiment leading to the concept of specificity.
A second experiment allows students to apply the techniques and concepts learned in the first activity and subsequent discussion to solve a mystery. Follow-up discussion and problems apply the concept of specificity to related topics. It can be used in association with topics such as allergies, food safety, or antigen-antibody precipitation. The major concept of this lesson is the specificity of the reaction between an antibody and an antigen. This concept will be illustrated through the use of an experimental procedure called a double diffusion assay.