To determine the blood type of unknown blood samples


Everyone has a unique blood type which allows us to be able to give or receive blood to only specific individuals. Receiving the wrong blood will result in our antibodies attacking the blood that is being transfused and destroying it. When antibodies bind to surface antigens, clumps can be seen indicating non-compatibility. The process is called agglutination.

Figure 1. Blood cell with surface antigens being attacked by antibody

A simple test can be done in the lab to determine blood type by combining a drop of blood with antibody A, B and Rhesus factor. If agglutination occurs with addition of A-antibody only, then the blood type is A negative. If agglutination occurs with both B antibody and rhesus factor, the blood type is B positive. I hope you get the picture.

Figure 3 is an example of agglutination occurring. Notice the grainy texture caused by the antibody binding to the antigens.

In this lab you are a clinical technician working at a big city hospital. There was a major accident resulting in several people needing blood. Four of the victims MUST be transfused within the hour to stay alive. Your job is to supply the medical team with the correct blood type information to save the life of these four victims.


Carolina® Transfusion Match with Synthetic Blood Kit


  1. Add three drops of synthetic blood on the blood test card (one for each spot labeled “blood”)
  2. Add one drop of antibody A, B and rhesus factor on the blood test card (these are shown as anti-A serum, anti-B serum, and anti-D serum on the card respectively)
  3. Use a tooth pick to mix blood and anti-serum (antibody) for about 20-30 seconds and leave to sit for about 5 to 10 minutes (Note: Use a fresh point each time. Do not cross contaminate)
  4. Check for agglutination
  5. Name the blood type based on your observation
Figure 2. Blood and antibodies on blood test card

Figure 3. Blood test showing agglutinated blood when mixed with antiserum A and B. This blood type is AB negative.

Lab Questions

  1. Name the blood type for
    • Victim 1 __________
    • Victim 2 __________
    • Victim 3 __________
    • Victim 4 __________
  2. Determine (showing your reasoning) if
    • A person with A negative type can donate to someone with a B negative type
    • A person with AB positive type can receive blood from someone with A negative type
  3. Which blood type is called the universal donor? Why are they able to donate blood to anyone?
  4. Which blood type is called the universal recipient? Why are they able to receive blood from anyone?
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Courtney Simons
Courtney Simons
Dr. Simons is a food science educator. He earned his bachelor’s degree in food science, and Ph.D. in cereal science at North Dakota State University.