Blood Typing Lab
Karl Landsteiner observed two distinct chemical molecules present on the surface of the red blood cells. He
labeled one molecule "A" and the other molecule "B." If the red blood cell had only "A" molecules on it, that
blood was called type A. If the red blood cell had only "B" molecules on it, that blood was called type B. If the
red blood cell had a mixture of both molecules, that blood was called type AB. If the red blood cell had
neither molecule, that blood was called type O. We know now, that these molecules are proteins, or
antigens.
If two different blood types are mixed together, the blood cells may begin to clump together in the blood
vessels, causing a potentially fatal situation. Therefore, it is important that blood types be matched before
blood transfusions take place. In an emergency, type O blood can be given because it most likely to be
accepted by all blood types. However, there is still a risk involved.
A person with type A blood can donate blood to a person with type A or type AB. A person with type B blood
can donate blood to a person with type B or type AB. A person with type AB blood can donate blood to a
person with type AB only. A person with type O blood can donate to anyone.
A person with type A blood can receive blood from a person with type A or type O. A person with type B
blood can receive blood from a person with type B or type O. A person with type AB blood can receive blood
from anyone. A person with type O blood can receive blood from a person with type O only. Because of
these patterns, a person with type O blood is said to be a universal donor. A person with type AB blood is
said to be a universal receiver.
Important Vocabulary
agglutination the clumping together of blood cells in response to a specific antibody
antigen any substance that will trigger an immune response by a host organism
antibodies compounds produced by plasma cells that react with specific antigens invading a body
plasma the fluid portion of blood that contains proteins and salts, and in which blood cells and platelets are
suspended
proteins essential constituents of all living things that are either made by the body or assimilated from food
transfusion the process of giving blood from one individual to another
The Scenario
You wake up to the loud ring of your cell phone, you answer and try to focus on the phone call. A crime has
been committed and you, because of your incredible problem solving skills and biological knowledge, are
being summoned to the scene of the crime.
When you arrive at the crime scene you are surprised to find yourself at Amador Valley High School, your
alma mater. For a moment you forget about the heinous crime you are here to investigate and begin to rack
your brain, trying to remember which teachers you tortured for four years. Quickly, you regain your
composure and get back to the task at hand. You greet Mr. Sira in the office and he leads you back to the
room where the crime occurred. Thankfully, due to his advanced age, he does not remember you. You walk
the halls back to the E-building; the walk brings back great memories. You wonder, is Mrs. Mistry, your
favorite, smartest, most beautiful, funniest, greatest, teacher from high school still there?
You are horrified when Mr. Sira begins to fill you in on the details of the crime. It seems Mrs. Mistry was
working late the previous day (as she always does to diligently prepare for her wonderful students) and
called her husband to tell him that she would be home by 11:00 pm. When she did not arrive by 11:30 Mr.
Mistry called the police and they went to her room at the school. Upon their arrival they discovered a
classroom in shambles. Microscopes were on the ground, sheep hearts and brains scattered all over the
room, but no sign of Mrs. Mistry. The only thing that they found was a piece of cloth stained with what looked
like blood. The police collected this cloth and Mr. Mistry confirmed that it appeared to be a piece of Mrs.
Mistry’s clothing.
You survey the room and notice that there are more bloodstains on Mrs. Mistry’s computer. Mr. Sira hands
you a list of suspects, you are shocked to learn that one is a former classmate. You ask what he would be
doing at Amador still and shockingly; you learn that he has not yet graduated. A bit confused, you collect
samples and get to work. If you can figure this out quickly enough there may be time to save your favorite
teacher ever.
Procedure
You remember from Mrs. Mistry’s class that Type A blood clots when mixed with anti-A serum. Type B blood
clots when mixed with anti-B serum. · Type AB blood clots when mixed with both anti-A and anti-B serums.
· Type O blood does not clot when mixed with either anti-A or anti-B serum. · Rh-positive blood clots when
mixed with anti-Rh serum. · Rh-negative blood does not clot when mixed with anti-Rh serum. You will
perform the following tests and record your results on your data table.
1. You have six well plates. Place them on top of a white piece of paper and label them appropriately.
a. Well Plate #1 = Crime Scene
b. Well Plate #2 = Victim
c. Well Plate #3 = Suspect # 1
d. Well Plate #3 = Suspect # 2
e. Well Plate #3 = Suspect # 3
f. Well Plate #3 = Suspect # 4
2. You will be using only three of the wells in the well plates (some have only three, some have more).
Put 2 drops of the blood from the victim in each of three wells in the victim tray.
3. Place 2 drops of the anti-A serum into one of the three wells containing the victim’s blood. Keep track
of which wells you are adding which serums to.
4. Place 2 drops of the anti-B serum into one of the three wells containing the victim’s blood. Keep track
of which wells you are adding which serums to.
5. Place 2 drops of the anti-Rh serum into one of the three wells containing the victim’s blood. Keep
track of which wells you are adding which serums to.
6. Stir each of the wells with a clean toothpick to mix the serum with the blood.
7. Check each well for an agglutination reaction, determine the blood type of the victim.
8. Repeat steps 2-7 for the remaining blood samples.
Blood Source
Crime Scene
Victim
Suspect 1
Suspect 2
Suspect 3
Suspect 4
Anti-A Serum
Anti-B Serum
Anti-Rh Serum
Blood Type
1. Why is it important for hospitals to have a ready supply of many different blood types?
2. What kinds of tests do you think are done on blood donations before they are used in transfusions?
3. Why is it important to know your own blood type?
4. If you were asked to testify in a court proceeding regarding your results, how would you summarize
your results to the jury?
5. How would you respond to the accused suspect’s denial of having the blood type that you identified,
since he has proof that he had just received a blood transfusion with type O blood?
6. Why is it necessary to type the victim’s blood?