Blood Typing
Blood Groups
• Karl Landsteiner in the 1900’s discovered blood typing.
ABO Blood Groups
• Based on 2 Antigens (agglutinogens)
• 4 blood types: A, B, AB, O
• Blood antigens are genetically coded located on the surface of RBC membrane
• Antigen found on RBC corresponds to blood type.
Blood Groups
• TYPE ANTIGEN PRESENT
– A A– B B– AB AB– O Neither A nor B
Blood Groups
• Antibodies are called agglutinins they develop after birth in the plasma
• You will have the antibody for the antigen that is NOT present.
• If you have A blood you have the A antigen on your RBC you will develop the B antibody
Antibody
• TYPE ANTIGEN ANTIBODY
• A A anti B
• B B anti A
• AB AB neither
• O neither anti A antiB
BLOOD TYPE PERCENTAGE
O 45%
A 40%
B 11%
AB 4%
• A reaction outside the body between antigens and antibodies result in agglutination which means the blood cells clump together.
• A reaction within the body between antigens and antibodies results in hemolysis which means the red cells burst
Rh Factors
• 1946 Landsteiner, Levine and Weiner did research on the rhesus monkey and developed the Rh factor
• Three genes code for the antigen on red cells- C, D, E
• Blood Types based on Rh
• Rh positive means the Rh antigen is present on the RBC (+)
• Rh negative means the Rh antigen is not present on the RBC (-)
• Rh negative people that receive Rh positive blood can have the immune system develop Rh antibodies that will remain in the blood
Erythroblastosis Fetalis
• Hemolytic Disease of the Newborn
• A Rh negative mom may be exposed to an Rh antigen from the blood of a Rh positive baby during pregnancy or birth.
• If Rh + cell enters Rh- mom the mother’s immune system will respond and produce antibodies against the Rh positive blood antigen
• In pregnancies thereafter Rh antibody may cause the placenta and cause RBC hemolysis in fetus. The baby will be anemic and very ill.
• This can be avoided by giving a Rh- mom antibodies in the form of a RhoGam shot within 72 hours after delivery of every Rh+ child
Blood Typing
• Blood typing is when blood samples are tested with known antiseras that contain known antibodies
O+
A+
B+
AB+
B+
o-
Cross Matching
• Cross matching is where typing the donor’s RBC’s are mixed with the recipients serum to check for compatibility before a blood transfusion
• http://nobelprize.org/educational_games/medicine/landsteiner/
• Go to this website and type some blood