The first blood typing system discovered, the ABO system, is the most important and widely used. In this activity, students will determine the ABO blood type of four unknown samples. Utilizing Innovating Sciences' new simulated blood, students will come to understand the nature and importance of antigen-antibody reactions. The most realistic simulated blood available, this activity provides the most realistic simulation of the actual blood typing procedure. Kit contains enough materials for 10 groups. Teacher's Manual and Student Study Guide copymasters are included.