When I was in 7th grade I had an amazing science teacher named Mrs. Hogan. She had a unique way of making science fun and exciting, and one of the most memorable experiments she had us do was on blood types. Ever since I did this experiment, I have always been able to remember which blood types are compatible. It takes very little set up, so it’s great to add-on to a homeschool anatomy unit or just for fun on a summer afternoon.
You can download the Blood Type Experiment instructions and worksheet for free at my TPT store here:
Blood Type Experiment Instructions:
Here’s what you will need:
4 clear cups
Post-it notes or a sharpie to mark the glasses
Red and blue food coloring
To set up the experiment:
1. Fill each glass about halfway with water
2. Label each glass with the different blood types: O, A, B, and AB (be sure to label them high on the glass or your water will obscure the labels like my ‘A’ cup here!)
3. Put several drops of red food coloring in the ‘A’ glass and stir
4. Put several drops of blue food coloring in the ‘B’ glass and stir
5. Put equal amounts of red and blue in the ‘AB’ glass and stir
You should now have 1 glass of clear water, 1 red, 1 blue, and 1 purple. The students can then use the Blood Type Compatibility sheet to chart which blood types are compatible.
The answer is found simply. If you can pour water from one cup into another without it changing the color of the receiving cup, then that blood type can receive the one you poured. For example, if I pour the red water from blood type A into the purple water of blood type AB, the water stays purple. This means that AB blood can accept type A blood. Here is a quick rundown of all the different outcomes:
O can receive only O blood.
A can receive both A and O blood
B can receive both B and O blood
AB can receive all blood types and is the universal receiver.
O is the universal donor – it can give to any blood type.
Note: this experiment does not deal with positive and negative blood types but is meant as an introduction to blood types
Older kids should be able to reason out the answers without having to actually pour the water, but younger kids really understand the concept when they try it out.
20 years later, I still can tell you quickly about blood types because of a great demo by Mrs. Hogan, and I now my own kids can chime in too!