Lesson 4: Blood Detectives
In this lesson, students will learn how to use a compound microscope to identify multiple blood diseases from the blood of various individuals.
• Use a compound light microscope to observe blood smears from individuals with blood disorders
• Distinguish between blood smears of healthy and unhealthy individuals
• Correlate changes in the blood with disease symptoms
• Diagnose diseases based on blood smear observations
• Blood Detectives Student Worksheet 4A and 4B
• prepared slides of blood smears from individuals with blood disorders (or high-quality color photos)
• compound light microscope (one for every one to two students)
1. Review categories of blood disorders and examples of each.
2. Observe blood smears from individuals with blood disorders at
10X and 40X magnification under the compound light microscope.
3. Sketch observations and answer all questions on the student worksheet.
4. Students should use their previous sketches of normal blood smears as a basis of comparison. You may also make the normal blood smears or color photos available for students to look at again.
5. Group students into teams of two to four. Distribute the history, physical symptoms, and microscope slides with blood smears of patients who have not yet been diagnosed (“unknown” samples). Teachers should use the ASH Web site to create accurate descriptions of the symptoms of specific diseases for which you have obtained blood smears. If you cannot obtain blood smears for all of the diseases you want students to diagnose, use color photographs instead.
6. Have students make observations and predict which disease the patient has based on the blood smears and the physical symptoms. The diagnosis has to be justified on their direct observations and information from previous lessons and/or the ASH Web site. Students should specifically cite the symptoms and changes in the blood smear that led to their diagnosis.
• Students can present their findings to the class in the form of a PowerPoint presentation. Have them include background information on the blood disorder they diagnosed, specific observations that led them to that diagnosis, and their recommendations for treatment.
• Assign students to research a well-known hematologist and create a scrapbook based on that person’s life. Students should include biographical information, career information, and a one-page reflection on the hematologist’s life.