1. BLOOD GROUPING
M.J. Afra
II – BSc Microbiology
Department Of Microbiology and Biotechnology
Thassim Beevi Abdul Kader College For Women Kilakarai

2. INTRODUCTION
• There are four main blood groups.
• They are A, B, AB and O
• Blood group is determined by the
genes you inherit from your parents
• Each group can be either RhD positive
or RhD negative
• Totally, there are eight main blood
groups

3. WHAT IS BLOOD?
• Blood is a fluid that transport oxygen
and nutrients to the cell
• Blood is made up of Red Blood Cells
(RCB), White Blood Cells (WBC) and
Platelets
• The RBC, WBC and Platelets present in
the liquid called Plasma.
• Blood group is identified by antibodies
and antigens in the blood

4. ANTIGENS AND ANTIBODIES
• Antibodies are proteins found in the
plasma
• They are the parts of our body’s
natural defenses
• They recognize the foreign
substances and destroy them
• Antigens are protien molecules that
are found on the surface of red blood
cells

5. ABO BLOOD GROUPING
• ABO blood grouping can be performed in
two ways:
1. FORWARD GROUPING / CELL GROUPING
2. REVERSE GROUPING / SERUM GROUPING
• Forward Grouping: Red blood cells ate
tested for A and B antigens using known Anti
– A and Anti – B sera
• Reverse Grouping: Serum is tested for Anti
– A and Anti – B antibodies using known A and
B red cells

6. • There are four main blood groups defined by
ABO system:
1. Blood Group A – has A antigens on the RBC with
Anti – B antibodies in the plasma
2. Blood Group B – has B antigens with Anti – A
antibodies in the plasma
3. Blood Group O – has no antigens but both Anti
– A and Anti – B antibodies in the plasma
4. Blood Group AB – has both A and B antigens,
but no antibodies
• Blood Group O is the most common blood group.
Almost half of the population has blood group O
ABO BLOOD GROUPING

7. THE Rh SYSTEM
• Red blood cells sometimes have another
antigen, a protein known as the RhD
antigen
• If RhD antigen is present, your blood
group is RhD positive
• If RhD antigen is absent, your blood group
is RhD negative
• About 85% of the population have Rh
positive

8. EIGHT MAIN BLOOD GROUPS
• A Positive (A+)
• A Negative (A-)
• B Positive (B+)
• B Negative (B-)
• O Positive (O+)
• O Negative (O-)
• AB Positive (AB+)
• AB Negative (AB-)

9. SAMPLE REQUIRED
• The blood grouping can be done on whole
blood or even on clotted blood
• The sample can be stored ay 4°C and
stable for 5 days
• Sometimes weak subgroups may result in
mistyping where Coombs test may be
helpful

10. INDICATIONS
1. ABO blood grouping and Rh typing are
done
2. Blood grouping is done for the donor
and recipient (Crossmatch)
3. Blood grouping is done in the expected
mother and new born

11. REAGENTS
• The blood grouping reagents
enables rapid identification
of ABO blood group and Rh
factor depending upon the
antigen present on the
surface of red blood cells

12. BLOOD GROUPING REAGENT
REAGENTS COLOR VOLUMES STORAGE
TEMPERATU
-RE
Anti A Sera Blue 5 ml 2-8° C
Anti B Sera Yellow 5 ml 2-8° C
Anti - D Clear 5ml 2-8° C

13. PROCEDURE
1. Inform the patient or individual about
the procedure to be carried out
2. Dangle the hand down to increase the
flow of blood in the fingers
3. Clean the fingertip to be pierced with
spirit or 70% alcohol and gently
massage the finger to increase blood
flow

14. PROCEDURE
4. With the help of sterile lancet or
pricker, pierce the fingertip and place one
drop of blood in each of the three cavities
5. Now add one drop of each of the
antiserum into each cavities respectively
6. Mix each blood drop with the antiserum
using a fresh mixing stick or applicator
stick

15. PROCEDURE
7. Now, we can observe the
agglutinations in the form of fine red
granules within 30 seconds
8. Anti RhD takes slightly longer time
to agglutinate compared to Anti A
and Anti B

16. EXPECTED RESULTS
SLIDE
NUMBER
ANTI A ANTI B ANTI RhD BLOOD
GROUP
Slide 1 ✔ ✖ ✔ A+ve
Slide 2 ✖ ✔ ✔ B+ve
Slide 3 ✔ ✔ ✔ AB+ve
Slide 4 ✖ ✖ ✔ O+ve
✔ - Agglutination
✖ - No
Agglutination

17. EXPECTED RESULTS
SLIDE
NUMBER
ANTI A ANTI B ANTI RhD BLOOD
GROUP
Slide 1 ✔ ✖ ✖ A-ve
Slide 2 ✖ ✔ ✖ B-ve
Slide 3 ✔ ✔ ✖ AB-ve
Slide 4 ✖ ✖ ✖ O-ve
✔ - Agglutination
✖ - No
Agglutination

18. EXPECTED RESULTS
• If agglutination is observed when individual’s
blood is mixed with Anti A reagent, then the
individual is said to have a blood group A
• If agglutination is observed when individual’s
blood is mixed with Anti B reagent, then the
individual have a blood group B
• If agglutination is observed when individual’s
blood is mixed with Anti A and Anti B reagent,
then the individual is said to have a blood group
AB

19. • If no agglutination is observed when
individual’s blood is mixed with Anti RhD
reagent, then the individual is said to have a
blood group O
• If agglutination is observed while mixing the
blood with Anti RhD reagent, then the
individual is said to have a +ve Rh factor
• If no agglutination is observed while mixing
the blood with Anti RhD reagent, then the
individual is said to have –ve Rh factor
EXPECTED RESULTS

20. REFERENCE AND SOURCES
• https://www.labtestsguide.com/blood-group-test-procedure
• https://www.britannica.com/science/blood-group
• IMAGE SOURCES
• http://google.com

21. THANK YOU