A hematocrit test determines the percentage of blood volume consisting of red blood cells. A blood sample is centrifuged in a capillary tube to separate the red blood cells, white blood cells/platelets, and plasma. A reader card is used to measure the percentage of RBCs. In this simulation, each time the "New Sample" button is clicked, a new sample will be produced. Each sample includes the patient age, sex, and hematocrit. A Google Doc virtual lab is available to use with this simulation. See the blog post for additional information.