Download Blood Typing Lab

Blood Typing Lab
Experimental Question
How do you determine which blood type is suitable to be donated or received in a blood transfusion?
Introduction and Background:
Humans can have the A, B, AB, or O blood type. The phenotypic differences are due to proteins anchored
in the red blood cell (RBC) membrane and in the blood plasma. The proteins anchored on the red blood cells act as
antigens and the proteins in the plasma act as antibodies. For example, type A blood has A antigens on the surface
of the red blood cells and B antibodies (anti-B) in the blood plasma, whereas type B blood has B antigens on the
surface of the red blood cells and A antibodies (anti-A) in the blood plasma. Type AB blood is unique because it has
both A and B proteins on the surface of the red blood cells, but no plasma antibodies. Type O blood is equally
unique because it has no antigens on the surface of the red blood cells, but has both A and B antibodies in the blood
plasma. Another protein anchored on the cell membrane of red blood cells is called the Rh factor. If an individual
has the gene that produces the Rh protein, their blood is considered Rh positive. So a person who has the A protein
and the Rh proteins has A positive blood. If an individual has the A protein, but no Rh protein, their blood is
considered A negative.
Blood type
A-
Antigen on RBC
A
Antibodies in plasma
B, and Rh
A+
BB+
AB AB +
O+
O-
A and Rh
B
B and Rh
A and B
A, B and Rh
Rh
None
B
A and Rh
A
Rh
None
A and B
A, B, and Rh
Mixing blood types has serious consequences. For example, when type A blood is mixed with type B blood,
the antigens on the type A red blood cells react with the plasma proteins of type B blood. This antibody-antigen
reaction causes severe clumping (agglutination) of the red blood cells. Agglutination tends to block blood vessels,
resulting in brain and kidney damage and, ultimately, death.
Those with type O negative blood are called universal donors. Although blood type O contains plasma
proteins against blood types A, B and Rh, it can be used in emergency transfusions as a donor to A, B, and AB blood
types since the proteins in this blood plasma become so diluted in the recipient’s plasma that the amount of
agglutination does not reach lethal levels. The O blood cells are not attacked by the anti-A and/or anti-B in the
recipient because the O cells do not contain any A or B antigens. Those with type AB positive blood are called
universal recipients since they have no plasma antibodies to react with the antigens found on A, B, and O types of
red blood cells.
Procedure:
1. With each blood sample, mix a few drops with the Anti-A, Anti, B and Anti-Rh solutions, which contain the
antibodies that bind to the respective antigen proteins.
2. Each blood sample should be tested with separate antibody solutions, so you will test each blood type for the
A, B and Rh proteins independently.
3. Check for agglutination (clumping) and record below for positive (agglutination) or negative (no
agglutination) reactions.
4. Based on your results note the blood type of each individual.
5. Determine which blood types each patient could receive as a transfusion.
Data:
Patient 1
Testing Solution
Antibody-A
Antibody-B
Antibody-Rh
Patient 2
Testing Solution
Antibody-A
Antibody-B
Antibody-Rh
Patient 3
Testing Solution
Antibody-A
Antibody-B
Antibody-Rh
Patient 4
Testing Solution
Reaction
Blood Type
(Clumping?)
Possible Blood Type(s) for
Transfusion
Reaction
Blood Type
(Clumping?)
Possible Blood Type(s) for
Transfusion
Reaction
Blood Type
(Clumping?)
Possible Blood Type(s) for
Transfusion
Reaction
Blood Type
(Clumping?)
Possible Blood Type(s) for
Transfusion
Antibody-A
Antibody-B
Antibody-Rh
Conclusions:
1. How do you determine which blood type is suitable to be donated or received in a blood transfusion?
2. Explain why a blood transfusion must match a patient’s blood type.
3. A and B blood are codominant, if two parents with AB blood have a child, what possible blood types would
you expect?
4. O blood is recessive to AB blood. What possible blood types could result from parents with O and AB
blood?
5. Based on the fact the Rh factor only has two phenotypes (+ or -) which are equally distributed between males
and females what type of inheritance (polygenic, complete dominance, sex-linked, incomplete dominance, or
multiple alleles) does the trait follow?
6. Assuming all blood types are equally common, people with what blood types would have the best and worst
odds of finding a donor?