Blood Type Testing Lab Report
Date of Lab: 12/03/2015
Members: Prow Janjarussakul (Prow)
Punyawee Lerdworawut (Earl)
Introduction
In this experiment, its purpose is to figure out the blood type of the donor. According to
Mendel’s research, there can only be two alleles contained in one gene. [2]There are exceptions,
however. Humans can have red blood cells containing types that are A: (IA), B: (IB) or O: (i). But an
individual can have only 1 type. These 3 can be combined in different ways such as, IA IA, IA IB, IAi , IBi and
ii. These are known as multiple alleles. In definition, they mean that an allele of genetic locus have more
than two allelic forms within a population.
The main components of blood are red blood cells, white blood cells, platelets and blood
plasma. Blood types have been classified through what are presented on the blood cell’s surface. If
there’s antigen-A presented, the blood type will be A. If there’s antigen-B the blood will be B. If there’s
both antigen-A and B presented, the blood will be AB and when there’s no antigen presented, the blood
will be O.
As there are many blood donations nowadays, blood transfusion to patients should be carefully
transferred. On each and every blood cell in the body contain antigens on their surface. Antigens are
abbreviated from ‘antibody generator’ that are usually proteins or polysaccharides. For example, a
person with blood type A will likely to have antigen-A presented on the blood cell, a person with blood
type AB will have both antigen A and antigen B on their blood cell and so on. But unlike blood type O, it
has no antigen presented on its blood cell surface. [4]
Since each blood type contains different antigens on their surface, it will be likely that it can only
receive certain blood types in blood transfusion. If a person has blood type A, meaning that they have
Anti-A on the blood cell’s surface, will likely to have antibody B in its plasma.
The reason is that the body does not have antibody A in its plasma is because the antibody will
bind to the A antigens presented on its blood cell and cause coagulation. Coagulation is when
precipitate forms and can clot small capillaries in the body. The antibodies in the blood plasma will not
have the same type as the antigens presented on the blood cell’s surface.
Antibodies are a common name for ‘immunoglobulins’. They are made by plasma cells that
come from B cells of the immune system. [3]These immunoglobulins are basically proteins that function
as antibodies. It has a large Y-shape and each antibody has a very specific receptor that has a unique
target that it would bind to. For example, antibody U will likely to bind with antigens U’s receptor that is
invading an organism.
Materials
1. 2 Microscope Slide
2. Lancet Device
3. Anti-A, -B, -AB
4. Ethanol
5. Markers
6. Cotton Ball
7. Lancets
8. 3 Toothpicks
Method
1. Turn the slides over and draw two circles with 1cm diameter each.
2. Label them like so:
C = control
A
C
B
AB
3. Puncture your finger by a qualified person.
4. Drop one blood drop in to each of the circle.
5. Drop
a. Anti-A : 1 drop of Anti-A
b. Anti-B : 1 drop of Anti-B
c. Anti-AB: 1 drop of Anti-AB
d. Control: DON’T PUT ANYTHING
6. Use toothpick to mix the blood. Change the sides or change the toothpick every time you mix
each of the bloods.
7. After waiting for 10 seconds, observe the results.
Results
Table 1: Blood coagulation with each antigen.
State: Coagulation / No coagulation
Control
no coagulation
Anti-A
coagulation
Anti-B
no coagulation
Anti-AB
coagulation
Picture 1: Two Slides containing blood drops and antigens.
*C = Control
Coagulation
No Coagulation
Picture 1:
This picture shows how the blood dots in each slide coagulate after putting in antibodies
in. As the labels suggest, circles A and AB seems to coagulate and C and B does not. Since A and AB
circles clot, we could conclude that the blood is A type.
Discussion
Taking the result into account, we can see that clotting of blood has occurred in slides A and AB.
We can conclude that the blood donated is an A blood type. The result seems to be true since the donor,
Prow, has an A blood type.
The reason we can use the blood clotting phenomenon to determine each blood type is because
when certain blood is in contact with an antibody of the same type, clotting will occur. To explain this
phenomenon, this experiment, the blood and Figure 1 will be used.
Suppose the blood is unknown, when the blood comes in contact with each of the antigen A, B
and AB some or none clotting will occur. ‘None’ of the clotting may occur are ONLY when the unknown
blood is an O blood type. An O blood cell has no antigens presented on its surface therefore, when it’s in
contact with all the antibodies we put in, there will be no coagulation. [3]O blood type is known as
‘universal donator’ as they can donate blood to anyone, and will not cause patient’s immune system to
start an attack.
In matters of other blood type (A, B and AB), in this type of experiment clotting will definitely
occur. If the unknown blood turns out to be a B blood, there will be precipitate forming in slides B and
AB. This could be explained using Figure 1. [2]The reason that there’s also clotting in slides AB is because
the antibodies AB (that are dropped on to the blood B) has antibody B that will bind to antigen B
presented on the B blood cells and cause clotting, and the same thing goes for B slide that contains
antibody-B. The antibody will bind to the antigens presented on the B blood cell and coagulation will
occur. However, if the unknown blood turns out to be Blood Type A, precipitates will form in slides A
and AB. The phenomenon is explained in the same way blood type B is explained. Moreover, if the
unknown blood is AB, there will be clotting in slides A, B and AB. This is because AB blood type contains
both A and B antigens on their surface and antibodies will all bind to them, causing coagulation. [3]AB
blood type is commonly known as ‘universal receiver’ as they can receive any blood type because they
do not contain A and B antibodies in their blood plasma. Therefore, no coagulation or any clotting will
occur.
Figure 1
Prow


Father = IA IB
Mother = ii
From crossing in Punnett Square as represented in
table one, Prow’s parents have these genotypes; father = IA
IB and mother = ii. Her possible genotypes when IA IB and ii
Table 2: Scenario one
IA
IB
A
i
Ii
IB i
i
IAi
IB i
are crossed are 50% blood type IAi and 50% blood type IBi.
The ratio of phenotype in this scenario is 1:1. Prow has 50%
chance of getting AO blood type and 50% chance of getting
a BO blood. There’s 0% chance of Prow getting an AB Blood
type and an O blood type.
Earl


Father = ii
Mother = ii
In table 3, Earl’s blood is ii (O) and represented in
Punnett Square. The only scenario that makes her blood an
O type is that both of her parents are O. As it can be seen in
Table 3: Scenario one
i
i
i
ii
ii
i
ii
ii
table 3, ii are crossed with ii making all the possible
genotypes all ii (O) therefore, the percentage of Earl being
an O blood type is 100%. There’s 0% chance that Earl will
get other blood types.
Conclusion
From this experiment, we found out that the blood drops that are on the slides are blood type
A. This is because precipitate has formed in the circles A and AB that contains antibody-A and antibodyAB. There has been no coagulation formed in circle neither B nor C. Therefore, the blood on the slides
are an A blood type.
References
[1]
American Red Cross (n.d) Blood Types (Online). Available: http://www.redcrossblood.org/learn-aboutblood/blood-types [Saturday. 14-March-2015]
[2]
Criswell, D. (2008) ABO Bloods and Human Origin (Online). Available: http://www.icr.org/article/aboblood-human-origins/ [Sunday. 15-March-2015]
[3]
Martin, L.J. (2014) Antibodies and Autoimmune Disorder(Online). Available:
http://www.nlm.nih.gov/medlineplus/ency/article/002223.htm [Sunday. 15-March-2015]
[4]
Jorgensen, J. (2004) Blood Groups and Red Cell Antigen (Online). Available:
http://www.ncbi.nlm.nih.gov/books/NBK2264/ [Monday. 16-March-2015]