Blood Grouping Experiment
An adult human has about 4–6 litres of blood
circulating in the body. Blood consists of
several types of cells including White Blood
Corpuscles or WBC and Red Blood Corpuscles
or RBC floating around in fluid called plasma.
There are certain protein molecules called
antigens located on the surface of the red
blood cells and antibodies which are in the
blood plasma. The differences in human blood
are due to the presence or absence of these
antigens and antibodies. Individuals have
different types and combinations of these
molecules.
According to the ABO blood grouping system
discovered by Karl Landsteiner, there are
four types of blood groups.
1. Blood Group A
2. Blood Group B
3. Blood Group AB
4. Blood Group O
Rh (Rhesus) factor is found on the RBC's surface
in most people. Like A and B, this is also
an antigen and those who have this antigen
are called Rh+. Those who lack this antigen
on the surface of RBCs are called Rh-.
To conduct the experiment we require:
• Three monoclonal antibodies - Anti-A,
Anti-B and Monoclonal D kept in an icebox.
• Lancets
• Spirit
• Cotton balls
• Tooth pick
• Glass slide
Procedure:
1. Swab the finger with alcohol swab and take
blood sample using a lancet as shown.
2. Take three separate drops of blood on a
glass slide.
3. Place a cotton ball on the finger to stop
the blood flow.
4. Now, pour one drop each of Anti-A, Anti-B
and Monoclonal-D on each drop of blood respectively.
5. Mix the monoclonal antibodies with the
blood sample properly using a tooth pick.
(Make sure you take a new tooth pick for mixing
each drop)
6. When RBCs carrying one or both antigens
are exposed to the corresponding antibodies,
they agglutinate; that is, they clump together.
7. For e.g., in this slide, agglutination
occurred on the first and third drops which
corresponds to antigen A and Rh factor. So
the blood group is A+.
8. Thus, we can identify the blood group by
noticing the agglutination on the corresponding
drops.
