1. Dr. Karl Landsteiner discovered the ABO blood group system in 1901 while studying agglutination reactions between red blood cells and serum. 2. The ABO system categorizes blood into four main groups - A, B, AB, and O - based on the presence or absence of antigens A and B on red blood cells. 3. The Rh system was discovered in 1937 and categorizes blood as Rh positive or Rh negative based on the presence or absence of the Rh antigen; Rh negative blood can only be transfused to Rh negative recipients.

1. BLOOD GROUP
Ferguson College ,Pune
Chemistry Department
[ Autonomous ]
Mangesh Jadhav

2. ABO BLOOD GROUP
 History
1. Dr. Karl Landsteiners discovered the
ABO Blood Group System in 1901
2. He and five co-workers began mixing each others red
blood cells and serum together and accidentally
performed the first forward and reverse ABO
groupings.
3. Landsteiners Rule: If an antigen (Ag) is present on a
patients red blood cells the corresponding antibody (Ab) will
NOT be present in the patients plasma, under ‘normal
conditions’.

3. I. THE ABO SYSTEM
 4 main phenotypes (A, B, AB, O)
 ABO gene located on long arm of
chromosome 9.
 Antigens/agglutinogens Type A and Type B
on the surface of the RBCs are the cause of
blood transfusion reactions [BTR]
 Thus, the presence or absence of these Ag’s
is the essential basis that blood is grouped
for the purpose of transfusion.
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6. n

9. FORMATION OF THE H ANTIGEN
Glucose
Galactose
N-acetylglucosamine
Galactose
H antigen
RBC
Fucose

10. Formation of the A antigen
Glucose
Galactose
N-acetylglucosamine
Galactose
RBC
N-acetylgalactosamine
Fucose

11. Formation of the B antigen
Glucose
Galactose
N-acetylglucosamine
Galactose
RBC
D-Galactose
Fucose

14. 14
ABO MARKERS
 Preformed antibodies
called agglutinins in
the plasma is unique
to the ABO blood
groups.
 Recall your Practical:

15.  Discovered by Landsteiner & Wiener in 1937
 Antigen discovered in the Rhesus monkey
 Rh is an Ag on the RBC
 a. Rh+ has the Ag (85% of the population)
 b. Rh- does NOT have the Rh antigens
 c. Rh+ can accept Rh+ or Rh- blood
 d. Rh- can accept ONLY Rh- blood
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ii. THE Rh SYSTEM

16. 16
RH FACTOR
There are 45 different types of Rh
agglutinogens.
 Common : C, D, and E
~ 85% of Americans are Rh positive, carrying
the D antigen.
Presence of the Rh agglutinogens on RBCs
is indicated as Rh+
As a rule, a person’s ABO and Rh blood
groups are reported together, for example,
O+, A-, and so on.

17. RH ANTIGENS
• D antigen is the most common and most
immunogenic
• Approximately 80-85% Caucasians have D
antigen
• Individuals lacking this allele are called “Rh-
negative”
• Only develop antibodies against the D
antigen after exposure
(transfusion/pregnancy)
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18. RH ANTIBODIES
• IgG class of immunoglobulins
• Lack capacity to bind complements
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20. SIGNIFICANCE OF RH(D)
 80% of Rh(D) negv persons exposed to Rh(D)
positive blood will develop anti-D.
 Anti-D can also be stimulated by pregnancy with
an Rh(D) positive baby
 Rh(D) neg females of childbearing potential
should never be given Rh(D) positive blood
products
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21. Characteristics of Bombay Phenotype
• First reported by Bhende et al in Bombay in
1952.
• Frequency estimated to be about 1 in 7600 in
Bombay.
• Absence of H, A & B antigens. No agglutination
with anti-A, anti-B or anti-H
• Presence of anti-H, anti-A and anti-B in the
serum
• No A, B or H substances present in saliva
• Incompatible with any ABO blood groups,
compatible with Bombay phenotype only

23. MICROSCOPIC
VIEWS
Bird Blood
Cat Blood
Dog Blood
Fish Blood
Frog Blood
Snake Blood
Human Blood
Horse Blood