WARD’S Simulated Blood Typing Lab
Name: ____________________________________________________________________
Agglutinogens (Antigens): Agglutinogens are substances found on the surface of erythrocytes.
Agglutinins (Antibodies): Agglutinins are antibodies found in plasma.
Agglutination: Occurs when antigens and antibodies of incompatible blood types form clumps or
clots.
E.g. Type B blood contains Anti-A antibodies. If Type B and Type A blood was mixed, Anti-A
antibodies from Type B blood will bind to antigens on the surface of Type A blood. The binding of
antibody to antigen forms complexes that precipitate.
DID YOU KNOW?
Donor blood contains only
packed red blood cells. There
is no plasma in donor blood,
thus there are no antibodies
present.
Table 1:
Complete the following chart on blood compatibilities:
Blood Type
Antigens on
Antibodies in
Can give blood
Erythrocytes
Plasma
to…
(agglutinogens)
(agglutinins)
A+
A
Anti-B
A, AB
B+
ABO-
Can receive
blood from…
O, A
Process of Agglutination:
There is a simple test to determine blood type, performed with antisera containing high levels of
anti-A, anti-B and anti-Rh agglutinins. Several drops of each kind of antiserum are added to
separate samples of blood. If agglutination (clumping) occurs only in the suspension to which the
anti-A serum was added, the blood type is A, etc. The absence of agglutination in any sample
indicates that the blood type is O. Any sample that agglutinates in the presence of anti-Rh serum
is considered Rh+.
Table 2:
Complete the following chart on blood typing reactions:
Reaction
Anti-A serum
Anti-B serum
Agglutination (yes)
No agglutination
Blood Type
A
B
AB
O
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SCENARIO
Crime investigators were called to the scene of a murder. Mr. Jackson was found dead at the
scene, succumbing to multiple stab wounds. The investigator noticed that as the murderer rushed
to leave the apartment, they ran into a glass door cutting their arm and tearing their shirt. The
crime investigators were able to remove blood samples from the broken glass door. The blood
samples from the crime scene, along with the victim’s blood, were sent to the forensic lab to be
analyzed. After the crime investigators carefully reviewed all of the available evidence, they
apprehended four suspects. The last remaining piece of evidence needed to solve the crime is to
match the blood type found at the crime scene with one of the suspects.
You will now determine the blood type of the victim, the four suspects, and the blood found at the
crime scene.
1. Use a wax pencil, sharpie, or tape to label each of your six blood typing trays as follows: [or
arrange the tray from left to right (Tray 1 to Tray 6)]
 Tray 1: Crime Scene
 Tray 4: Suspect # 2 (Mr. Jones)
 Tray 2: Victim (Mr. Jackson)
 Tray 5: Suspect # 3 (Mr. Green)
 Tray 3: Suspect # 1 (Mr. Smith)
 Tray 6: Suspect # 4 (Ms. Brown)
2. To determine the type of blood found at the crime scene, place 1-2 drops of the crime
scene blood in each of the A, B, and Rh wells of tray 1.
3. Place 3-4 drops of simulated anti-A serum on the blood sample in well A of the tray.
4. Place 3-4 drops of simulated anti-B serum on the blood sample in well B of the tray.
5. Place 3-4 drops of simulated anti-Rh serum on the blood sample in well Rh of the tray.
6. Obtain 18 toothpicks. Stir each sample of anti-serum and blood samples with a separate
clean toothpick for 30 seconds. To avoid splattering the simulated blood and scratching the
tray (which will obscure your results) do not press too hard on the typing tray.
7. Record your observations in table 3 of the analysis section. To confirm agglutination, put
your sample tray over your page and try to clearly read the text through the liquid in the
2
well. If you cannot read the text, assume you have a positive agglutination reaction. It
should also look slightly granular, not clear.
No Agglutination
Agglutination
Now you must determine the blood types of the victim and the four suspects.
Note: for this section, please do one test at a time to avoid mixing up samples and getting
incorrect results!
8. Place 1-2 drops of the victim’s (Mr. Jackson) blood in each of the A, B, and Rh wells of
Tray 2: Victim.
9. Place 1-2 drops of the simulated anti-A serum in the A well.
10. Place 1-2 drops of the simulated anti-B serum in the B well.
11. Place 1-2 drops of the simulated anti-Rh serum in the Rh well.
12. Gently stir each sample with a clean toothpick for 30 seconds. Use a new toothpick every
time you test to avoid contamination.
13. Place 1-2 drops of Suspect # 1’s (Mr. Smith) blood in each of the A, B, and Rh wells of tray
3.
14. Repeat steps 9-12.
15. Place 1-2 drops of Suspect # 2’s (Mr. Jones) blood in each of the A, B, and Rh wells of tray
4.
16. Repeat steps 9-12.
17. Place 1-2 drops of Suspect # 3’s (Mr. Green) blood in each of the A, B, and Rh wells of tray
5.
18. Repeat steps 9-12.
19. Place 1-2 drops of Suspect # 4’s (Ms. Brown) blood in each of the A, B, and Rh wells of
tray 6.
20. Repeat steps 9-12.
21. Record your observations in table 3.
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ANALYSIS
Table 3:
Blood Source
Crime Scene
Victim
Suspect # 1
Suspect # 2
Suspect # 3
Suspect # 4
ASSESSMENT
Anti-A Serum
Anti-B Serum
Anti-Rh Serum
Blood Type
1. As a forensics technician, the courts have asked you to summarize your findings to the jury.
Explain what you would say in the space below (remember, it is your job to report the facts,
not decide who is guilty)
2. Pick one of the following suspects:
Suspect #1 Suspect #2 Suspect #3 Suspect #4
a. Suspect #: ________
b. Using the information from Table 1 and the data from your blood type analysis in Table
3, what ABO agglutinogens (antigens) are present on the suspect’s red blood cells?
_______________
c. What ABO agglutinins (antibodies) are found in the suspect’s blood plasma?
d. What is the suspect’s blood type?
e. If the suspect needed a blood transfusion, what blood types could he/she receive?
______________________________________________________
f. What blood types could safely receive this suspect’s blood? ____________________
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3. Why is it necessary to type the victim’s blood?
4. One of the suspects claims you misidentified their blood type. They came forth with proof
that they recently received a blood transfusion of type O blood. How would you respond to
this claim? Does this help the suspect’s argument of innocence?
5. You are a defense attorney representing the accused. Your client has been shown to have
the same blood type as that found at the scene of the crime. Explain to the jury why this
information alone is not enough to convict your client. What would they need to concretely
convict them?
6. Many times, a suspect may attempt to clean the area containing a blood stain at the scene
of a crime. One tool utilized by forensic investigators is a substance called luminol.
Research luminol and explain how it may be used to aid investigators at a crime scene.
http://science.howstuffworks.com/luminol.htm
http://chemistry.about.com/od/glowinthedarkprojects/a/luminolblood.htm
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