This activity creates a model of blood inside a bottle using food coloring, cereals, marshmallows, and pom poms to represent plasma, red blood cells, white blood cells, and platelets. It helps students visualize the different components of blood and their functions.

1. Fill a large plastic bottle with about 1–1.5 liters of water.
2. Add 2 drops of yellow food coloring and 1 teaspoon of salt to represent plasma with dissolved minerals and nutrients.
3. Add red food coloring, one drop at a time, until the water has a deep blood-like color.
4. Place oat hoops in a ziplock bag, add red food coloring, and shake until they are evenly coated to represent red blood cells.
5. Add the red oat hoops to the bottle.
6. Add a handful of mini white marshmallows to represent white blood cells.
7. Add purple pom poms (or raisins if unavailable) to represent platelets.
8. Seal the bottle and gently swirl to see the mixture of blood components.

Make Your Own Blood Jar - BME HealthReach:

Daily Dose of Play - (Grades 6-8) Blood Model Activity - Children's Discovery Museum:

📄 Blood Model in a Bottle - Cambridge Science Centre: https://www.petersfield.cambs.sch.uk/site/petersfield/reactFiles/pdfs/OpenUpScienceIssue9BloodDigital.pdf

• Use rice or lentils dyed red as an alternative to oat hoops for red blood cells.
• Replace marshmallows with cotton balls for white blood cells.
• Use beads instead of pom poms for platelets.

• Food coloring may stain—cover surfaces and wear old clothing.
• Do not eat the model contents.
• Supervise young children with small items such as pom poms and marshmallows (choking hazard).

• What does each material in the bottle represent? (Oat hoops = red blood cells, marshmallows = white blood cells, pom poms = platelets, colored water = plasma.)
• Why is plasma important in blood? (It carries nutrients, dissolved substances, and waste around the body.)
• What role do platelets play when you get a cut? (They help blood clot and form scabs to stop bleeding.)
• Why is blood red? (Because of the presence of hemoglobin in red blood cells, which binds oxygen.)