EXPERIMENT NO 0
Objective:
To find out your own blood group.
Requirement:
Three glass slides, Anti sera A, Antisera B, Antisera D with separate droppers and Lancet.
Principle:
The principle of the experiment is to find out the blood group by mixing the blood with
the Antiserum and observe the agglutination by antigen antibody reaction.
Theoretical Explanation:
At least 100 antigen can be recognized and more than 15 systems of well define antigens
have been known, out of many antigen type A and type B are important which constitute
OAB system. People are Rh +ve or Rh –ve
In OAB system either both agglutinogens are present on the surface of RBC ,one of them
present or both of them are absent on the surface of RBC .On this basis the population may
be divided in to four blood group i.e .O,A,B,AB These are developed genetically according
to genotypes.
Blood group with their genotypes and Agglutinogen+agglutinins:
Genotype
OO
OA or AA
OB or BB
AB
Agglutinogens
A
B
AB
Agglutinins
Anti A& Anti B
Anti B
Anti A
-
Blood group
O
A
B
AB
%
47%
41%
9%
3%
The agglutinins are globulin which develops spontaneously due to A and B antigens which
enter the body in food, bacteria and in other ways. Most naturally occurring antibodies to
ABO antigen are Ig M class Rh antibodies are Ig G. Blood group antigens are present in
surface of RBCs.
Procedure:
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Take 3 dry glass slides and put them on the table.
Mark the slides Antisera A, Antisera B and Antisera D.
Put one drop of each antisera, using a separate dropper.
Prick the finger.
Add one drop of blood to each slide and mix well with the help of mixer.
Observe each slide for agglutination in bright light.
Assess the observation ,find out the blood group
The reagents used for ABO blood group determination are anti-A and anti –B. Both are Ig
M antibodies. These are commercially available standardized antibodies.
Clinical Significance:
1
When blood transfusion is necessary, the blood typing of the recipient and the
donor should be done very carefully, to avoid hazards of blood transfusion.
The mismatched blood transfusion result in to hemolytic jaundice and transfusion
reaction associated with hemolysis, haemoglobinurea and severe type of anemia.
Erythroblastosis Fetalis is a hemolytic disease of new born characterized by progressive
agglutination and subsequent phagocytosiss of RBC .If father is Rh+ve, mother is Rh –ve
and child has inherited Rh +ve antigen from father. The mother develops Anti Rh
antibodies that diffuse through placenta in to the fetus to cause RBC agglutination.
Prevalence of disease Rh –ve mother having her first Rh +ve child does not does
not develop this disease but 3% of second and10% of third baby develop erythroblastosis
fetalis and they are born with severe anemia in which many blast forms appear in circulation.
The incidence rises progressively with subsequent pregnancies.
Hemolytic transfusion reactions occur mainly due to ABO and Rh system.
Observation chart:
Antisera
Antisera A &1 drop
of blood
Antisera B & 1dop
Antisera D& 1
of blood
drop of blood
Agglutination
Agglutination = +ve
No agglutination= -ve
Result:
My blood group is =__________
The Rh +ve person has Rh antigen but no antibodies.
Rh –ve person neither Rh antigens nor antibodies.
Rh antibodies do never develop spontaneously until and unless Rh –ve person is exposed to
Rh antigen.
ABO and Rh blood group are of main importance in routine use.
Some other blood group include MNS ,P, Kell ,Duffy ,Kids, Lewis etc and a very important
Rh group.
Precautions:
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Slides should be washed and dried carefully.
Separate dropper should be used for each antisera.
The blood drop should not be touched to antisera.
A separate mixer should be used for mixing.
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