Labs and Activities

Week 8 – Blood Type

Learning Objectives

Upon completion of this learning package, the student will be expected to recall the following.

  • Recall the characteristics of each of the following components:
    • antigen
    • antibody
  • Name the major blood group classifications
  • Describe the genetically-determined antigens used in identifying the two major human blood groups, considering:
    • names of three genetically-determined antigens
    • location of antigens in blood
    • synonym used in reference to blood antigen
  • Describe the genetically-determined antibodies which may be found in human blood depending on the blood antigen present, considering:
    • names of two genetically-determined antibodies
    • location of antibodies in the blood
    • synonym used in reference to blood antibody
  • State the three principles, given below, that identify which genetically-determined antibodies are present in human blood:
    • plasma never contains antibodies against genetically-determined antigens on the red blood cells
    • plasma contains antibodies against genetically-determined antigens of the ABO classification not present on the red blood cells
    • in the Rh classification, Rh antibodies are not normally found in the plasma of Rh- people
  • Explain why an Rh- individual would develop Rh+ antibodies after receiving a transfusion of Rh+ blood.
  • Describe and explain the physiological events which are of concern when an Rh- mother is pregnant with an Rh+ fetus:
    • The first time
    • A second time
  • Define the term transfusion reaction.
  • Define each of the following terms associated with a blood transfusion reaction:
    • Agglutination
    • hemolysis
  • State the two principles which determine whether a major or minor blood antigen-antibody reaction (transfusion reaction) will occur:
    • a major transfusion reaction occurs when the recipient receives donor antigens. This results in the recipient producing antibodies which agglutinate the donor’s red blood cells.
    • minor transfusion reaction occurs when the recipient receives donor antibodies which agglutinate some of the recipient’s red blood cells
  • Explain how the agglutinated red blood cells affect the:
    • blood vessels
    • kidney
    • brain
    • individual’s mortality

 

Lab Activity 

When determining blood type we are attempting to describe the molecular shapes (antigens) present (or absent) on the surface of a red blood cell. For example, when considering the ABO blood types, if someone has type A blood, then it means their red blood cells have a molecular shape which we have designated A (antigen A). If someone has type B blood, their red blood cells have a molecular shape we have designated B (antigen B). If someone has type O blood then it means their red blood cells do not have the antigens A or B.

In order to determine which antigens are on the surface of the red blood cells we need specific ‘tags’ for each molecular shape. i.e. we need a molecule which will bind only to ‘A’ whenever A is present. If we mix the red blood cells and the ‘tag’ for A together we watch to see if there is binding. If binding occurs then we know these cells have the antigen A on their surface. If binding does NOT occur then we know the A antigen is NOT present. The specific tags used to determine blood types are antibodies.  For the ABO blood typing there is an antibody A (binds only to the A antigen on the red blood cell surface) and an antibody B (binds only to the B antigen on the red blood cell surface).

We can tell that binding has occurred by looking for agglutination of the blood. Antibodies are bivalent (i.e. have two binding sites). If the red blood cell has the A antigen, then antibody A will bind to it. Since the antibody has a second site for another A antigen it will bind to a second red blood cell. When we look at the blood, the red blood cells are clumped together and the surrounding fluid is ‘straw’ colored. This ‘clumping’ is called agglutination. The red blood cells are linked together due to ‘bridges’ of antibody molecules between them.

Materials Required:

  • Four different blood samples (labeled I, II, III, & IV)
  • Anti-A, Anti-B and Anti-Rh serum
  • Blood typing slides
  • Mixing sticks, absorbent mat, gloves, apron & goggles
  • Download Blood Sample Data Sheet [DOCX] to use during this lab activity.

Part A: Determination of Blood Type (ABO AND Rh)

  1. Put on a lab coat, goggles and gloves. Using a paper towel, wipe the tray with 10% bleach. Discard the paper towel in the Biohazard container.
  2. Cover the tray with an absorbent mat and place one blood typing slide and 3 toothpicks on the mat.
  3. Place one drop of blood in each of the 3 depressions, labeled A, B & Rh, on the blood typing slide.
  4. Add one drop of Anti-A serum (containing Anti-A antibodies) in the first depression A and mix it with the blood using a mixing stick. Leave the mixing stick on the mat.
  5. Repeat step 4, using Anti-B serum (containing Anti-B antibodies) in the second depression B, and then in the third depression using Anti-Rh serum. Use a new clean mixing stick for each serum.
  6. Check for agglutination in each depression to determine your sample’s blood type. You may have to wait for 20-30 seconds. To help you see agglutination you may gently tilt the slide back and forth.
  7. Record your results in the table below. Discard the absorbent mat, blood typing slide and mixing sticks in the Biohazard container.
  8. Using a paper towel clean the tray with 10% bleach and discard the paper towel, along with your gloves and apron in the Biohazard container and wash your hands. Make sure that you return the materials to their original location for next use.
  9. Record your observations in the Blood Sample Data Sheet of this package.

QUESTION:  Define agglutination.

Discussion

  1. In which parts of the experiment did agglutination occur?
  2. What antigens are present on this person’s red blood cells?
  3. What is this person’s blood type?
  4. What antigens are foreign to this person?
  5. What types of antibodies might this person produce?
  6. What types of blood can you give this person and what types can’t you give this person?
  7. If you were giving this person blood what types of blood would cause:
    1. a major transfusion response?
    2. a minor transfusion response?
Table 8.1 Blood Groups
Blood Group Reaction with anti – A Reaction with anti – B Antigens on surface of red blood cells Antibodies in blood plasma Can give blood to Can receive blood from
O – – None anti – A

anti – B

 O, A, B, AB O
A + – Antigen-A anti – B A, AB O, A
B – + Antigen-B anti – A B, AB O, B
AB + + Antigen-A

Antigen-B

 none AB O, A, B, AB

Worksheets

Complete the following tables.

Download Week 8 Lab Worksheet [DOCX] to print and fill out.

 

Part I:  Complete the chart, identifying the antigens and antibodies for each blood group

Blood Group Antigen

On [blank]

 Antigen

In [blank]
A
B
AB
O
Rh+
RH-

 

Part II:  Determine the specific antigens and antibodies present in each of the following blood types

Human Blood Type A+ B- AB+ O-
RBC Antigen(s)
PLASMA Antibody(ies)

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