ABO-Rh Blood Typing With Synthetic Blood

Full text

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70-0101

ABO-Rh Blood Typing

With Synthetic Blood

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The ability to type blood is an invaluable tool in the fields of medicine and criminology. Using this kit, students test four simulated blood samples to identify their ABO and Rh blood types. While the test procedures used in this kit are those used to test real blood, this kit contains synthetic blood and synthetic antisera. This eliminates any risk associated with exposure to actual blood or blood products. The materials in this kit may be discarded after use. There are no biological materials in the synthetic blood or synthetic antisera that would cause any health hazard when discarded.

Materials

Included in the kit

30 blood typing slides synthetic blood

synthetic anti-Rh (D) serum synthetic anti-A serum synthetic anti-B serum

mixing sticks (blue, yellow, and white) 30 Student Instructions

Objectives

• Perform standard tests used for blood type identification

• Understand the importance of blood type identification and its uses

• Learn about the form and function of blood components

National Science Standards

This kit can be used to address the following National Science Education Content Standards:

• Abilities necessary to do scientific inquiry

• Understanding about scientific inquiry

• Structure and function in living systems

• Understanding of the cell

• Matter, energy, and organization in living systems

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Preparation

Set up a workstation where students can obtain the synthetic blood and synthetic anti-serum samples they will need to complete this activity. Review the designations of the blood groups (A+, A–, etc.) and their agglutination reactions before beginning the lab. Each student will need a copy of the student instructions and a blood typing slide. Have the students go to the workstation and follow the instructions to test each synthetic blood.

Final Activities

After the tests of all four blood types have been completed and the results recorded, students should clean their blood typing slides. Be certain that all mixing sticks have been discarded.

Have the students compare their results. If a student has a result that differs from that obtained by the rest of the class, discuss what may have happened, such as

• contamination of sample • sample not sufficiently mixed • not enough time to view the reaction • wrong anti-serum in the well

• wrong blood sample in the well

Sample Questions for Assessment

The questions that follow can be used to check for student understanding of the ABO and Rh blood groups and their importance. The answer to each question is in italics.

1. Given the antigen(s) found on the red blood cells, give the corresponding blood antibody and the ABO blood type.

Blood Type

A

B

AB

O

Red Cell Antigen

A B AB Neither

Antibody in Blood Plasma

Anti-B

Anti-A

Neither

Anti-A, Anti-B

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2. For each of the given blood types, give the expected agglutination

results when the blood is mixed with each antibody.

3. At 1:00 a.m., someone breaks a window in the back of a store and robs

the safe. On the way out, the thief cuts himself (or herself) on a piece of broken glass. You are a forensic detective called to the scene. You test a sample of blood left behind by the thief. It is O–. While you are there, police bring in a suspect with a cut forearm who was arrested just three blocks from the store. You take a sample of the suspect’s blood and mix it with anti-A. You immediately know that the suspect is not the person who cut himself on the broken glass in the store. How do you know this?

The blood agglutinated, indicating the presence of the A antigen. This would not have happened if the suspect had type O blood. Note that this does not mean that the suspect was not involved in the break-in. It does mean that the blood at the crime scene could not have come from the suspect.

4. (Continued from Question 3) Suppose the suspect’s blood does not

agglutinate when tested with anti-A or anti-B, but does agglutinate when tested with anti-Rh. Would this connect the suspect with the crime scene? Explain your answer.

No. The blood left at the crime scene was O–. The suspect’s blood tested O+.

5. Tom and Jane participate in a Red Cross blood drive. Both are

first-time donors. As part of the screening process, their blood is typed. Tom is A+. Jane is AB+. What blood group antibody is found in Tom’s blood? Anti-B.

Blood Type

A+ A– B+ B– AB+ AB– O+ O–

Anti-A

Yes

Yes

No

No

Yes

Yes

No

No

Anti-B

No

No

Yes

Yes

Yes

Yes

No

No

Anti-Rh

Yes

No

Yes

No

Yes

No

Yes

No

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What blood group antigens are found in Jane’s blood? A, B, and Rh.

6. (Continued from Question 5) Tom and Jane’s blood donations are sent to a processing center where their blood cells are separated from their plasmas. Both their separated cells and plasmas are then sent to a hospital. A blood researcher wishes to use Tom’s blood in an attempt to extract and identify the A antigen. Should she attempt the extraction process on his blood cells or on his plasma?

The blood cells. The antigens are part of the cell membranes of the blood cells.

Optional Activity

You may want students to observe the different kinds of blood cells. This is easily done with prepared blood smears.

Materials

Needed, but not provided compound microscopes

Human Blood Film, smear (Carolina catalog #31-3158) Human Sickle Cell Anemia, smear (Carolina catalog #31-7374)

Human Acute Granulocytic Leukemia, smear (Carolina catalog #31-7404) Procedure

Have the students examine the normal human blood film under 400–450× magnification. They will immediately see the red blood cells. Careful examination of these cells may enable the students to infer their basic shape as being biconcave disks. They should also see red blood cells in various degrees of flexure. White blood cells are much less numerous, and it will take some searching to find them. With Wright Stain, several types of white blood cells can be distinguished. Students can simply observe that there are different types of white blood cells, or they can try to identify them. Textbooks often contain illustrations of the different white blood cell types, which will aid in their identification. Basophils have cytoplasmic granules that stain blue. The cytoplasmic granules of eosinophils stain bright red, and those of neutrophils stain paler than those of basophils. (Because of their cytoplasmic granules, basophils, eosinophils, and neutrophils are collectively called granulocytes.) Lymphocytes have a nucleus that stains blue. Monocytes also have a blue nucleus, but it is distinctly bi-lobed. Platelets are much smaller than any of these cells. They tend to form blue-stained clusters.

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Once students are familiar with the appearance of a normal blood film, they can examine sickle cell anemia and lymphocytic leukemia smears. How do they differ from the normal smear? Students can be assigned to research and report on these and other disorders that cause changes to the forms or relative abundance of the different blood cells.

Discussion

By volume, blood tissue is approximately 55% plasma and 45% cells. Plasma is a straw-colored liquid consisting of 90% water and a variety of salts and proteins. These components are important for maintaining osmotic balance, buffering against pH changes, maintaining blood viscosity, transporting certain materials through the blood, and blood clotting when an injury occurs to a blood vessel.

There are three major types of blood cells—red blood cells (erythrocytes), white blood cells (leukocytes), and platelets.

Red blood cells, the most numerous cells in the blood, carry oxygen from the lungs to all parts of the body. A red blood cell is shaped like a

biconcave disk with a thin center. This shape provides a large surface area for the diffusion of oxygen. Red blood cells contain the protein

hemoglobin. Iron, which is incorporated into the hemoglobin molecule, combines with oxygen as the cells travel through the lungs. While moving throughout the body’s capillary system, the oxygen is released to the other body cells. The flexibility of red blood cells allows them to carry oxygen through even the smallest blood vessels.

White blood cells make up only about 1% of the blood volume. They are an important part of the immune system. Their primary function is to provide a defense mechanism against invaders in the body, such as bacteria, parasites, fungi, and viruses. The cells may either attack a foreign body directly, produce antibodies that will identify the foreign body, attach to it and neutralize it, or trigger other cells to act in destroying the foreign body. Platelets perform a vital function in the process of coagulation, or blood clotting, which occurs when a blood vessel is injured.

The basic composition and function of blood in each of us is the same, but there are different blood types.

Blood Types

It will aid the students’ understanding if they are familiar with the Fluid Mosaic Model of the cell membrane. The cell membrane of red blood cells, like that of other cells, has molecules that project from its surface. Some of

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these molecules function somewhat as identification badges. They allow the immune system to recognize the cell as a normal component of an individual’s body. If red blood cells from another person are introduced into the bloodstream, they may have surface molecules that are different. These molecules, which are recognized as foreign to the body, are called antigens. The immune system then attacks these antigens and attempts to destroy them and the cells that carry them.

The ABO blood groups result from the presence or absence of two antigens, A and B, on the surface of the red blood cells. The immune system produces an antibody in the plasma for the antigen not present. Usually, it is necessary for exposure to an antigen to occur before antibodies are produced; however, in this instance the antibodies are already present. Type A blood has the A antigen on its red blood cells and anti-B antibodies in the plasma. Type B blood has the B antigen on its red blood cells and anti-A antibodies in the plasma. Type AB blood has both A and B antigens on the red blood cells and no antibodies in the plasma. Finally, Type O blood has neither A or B antigens on the red blood cells and there are both A and B antibodies in the plasma. The relationships of the ABO blood groups to the antigens and antibodies are summarized in the table below.

The ABO Blood Groups

Another important antigen found on the surface of blood cells is the Rh factor, named for the Rhesus monkey in which it was first discovered. Blood containing this antigen is said to be Rh positive (Rh+); blood lacking this antigen is said to be Rh negative (Rh–). The production of an Rh antibody requires exposure to the antigen.

Blood Group

A B AB

O

Red Cell Antigen

A B A and B Neither

Serum Antibody

Anti-B Anti-A Neither Anti-A and Anti-B

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Student Instructions Key

(answers in italics)

1. Using the dropper vial, place a drop of the first synthetic blood sample in each well of the blood typing slide. Replace the cap on the dropper vial. Always replace the cap on one vial before opening the next vial to prevent cross contamination.

2. Add a drop of synthetic anti-A (blue) to the well labeled A. Replace the cap.

3. Add a drop of synthetic anti-B serum (yellow) to the well labeled B. Replace the cap.

4. Add a drop of synthetic anti-Rh serum (clear) to the well labeled Rh. Replace the cap.

5. Using a different color mixing stick for each well (blue for anti-A, yellow for anti-B, white for anti-Rh), gently stir the synthetic blood and anti-serum drops for 30 seconds. Remember to discard each mixing stick after a single use to avoid contamination of your samples. 6. Carefully examine the thin films of liquid mixture left behind. If a film

remains uniform in appearance, there is no agglutination. If the sample appears granular, agglutination has occurred. Determine the blood type of the sample using the data table below. Answer yes or no as to whether agglutination occurred in each sample. A positive agglutination reaction indicates the blood type.

7. Record the results for the first blood sample in the data table.

8. Thoroughly rinse the blood typing slide, then repeat steps 1 through 7 for synthetic blood samples 2, 3, and 4.

Data Table

Sample 1

Sample 2

Sample 3

Sample 4

Anti-A

Yes

No

Yes

No

Anti-B

No

Yes

Yes

No

Rh

Yes

Yes

No

Yes

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Carolina Biological Supply Company

2700 York Road • Burlington, NC 27215 800.334.5551 • www.carolina.com

CB000000000 © 2 0 0 3 C a r o l i n a B i o l o g i c a l S u p p l y C o m p a n y

Student Instructions Name

70-0101 Date

ABO-Rh Blood Typing With Synthetic Blood

1. Using the dropper vial, place a drop of the first synthetic blood sample in each well of the blood

typing slide. Replace the cap on the dropper vial. Always replace the cap on one vial before opening the next vial to prevent cross contamination.

2. Add a drop of synthetic anti-A (blue) to the well labeled A. Replace the cap. 3. Add a drop of synthetic anti-B serum (yellow) to the well labeled B. Replace the cap. 4. Add a drop of synthetic anti-Rh serum (clear) to the well labeled Rh. Replace the cap. 5. Using a different color mixing stick for each well (blue for A, yellow for B, white for

anti-Rh), gently stir the synthetic blood and anti-serum drops for 30 seconds. Remember to discard each mixing stick after a single use to avoid contamination of your samples.

6. Carefully examine the thin films of liquid mixture left behind. If a film remains uniform in

appearance, there is no agglutination. If the sample appears granular, agglutination has occurred. Determine the blood type of the sample using the data table below. Answer yes or no as to whether agglutination occurred in each sample. A positive agglutination reaction indicates the blood type.

7. Record the results for the first blood sample in the data table.

8. Thoroughly rinse the blood typing slide, then repeat steps 1 through 7 for synthetic blood samples 2,

3, and 4.

Data Table

Sample 1 Sample 2 Sample 3 Sample 4

Anti-A Anti-B Rh Blood Type

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Carolina Biological Supply Company

2700 York Road, Burlington, North Carolina 27215 Phone: 800.334.5551 • Fax: 800.222.7112 Technical Support: 800.227.1150 • www.carolina.com

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