Table of Contents
What Is Blood Typing?
Blood typing is a scientific test used to determine a person's blood type. The test is of utmost importance in blood transfusion or blood donation cases. This test is also carried out to see the presence of the Rh factor on the surface of red blood cells. Blood typing is based on the presence of certain proteins called antigens on the surface of red blood cells. The blood group (blood type) depends on the blood group passed down from your parents to you. Karl Landsteiner, an Austrian scientist, discovered the blood groups in 1901.
What Are the Blood Types?
Blood typing is usually done according to the ABO blood typing system. The four major categories of blood are:
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Type A- It has got A antigen.
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Type B- It has got B antigen.
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Type AB- It has got both A and B antigens.
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Type O- It has got neither A nor B antigens.
It is important to know your blood type. Receiving a blood sample incompatible with your blood group might cause a dangerous immune reaction. Blood types are further categorized by Rh (Rhesus) factor:
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Rh-Positive: People having Rh-positive blood group consist of Rh antigens on the surface of erythrocytes. These people can receive blood both from Rh-positive and Rh-negative blood group people.
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Rh-Negative: People having Rh-negative blood groups lack Rh antigens. Therefore, these people can receive only Rh-negative blood.
Hence, the ABO and Rh blood typing systems determine an individual's complete blood typing profile. Together, there are eight possible blood types:
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O-positive blood group.
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O-negative blood group.
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A-positive blood group.
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A-negative blood group.
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B-positive blood group.
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B-negative blood group.
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AB-positive blood group.
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AB-negative blood group.
Why Is Blood Typing Important?
Blood typing is carried out before the process of blood transfusion or donation of blood. Blood typing is a safe, quick, and easy way to ensure that the patient receives the right blood group during surgery or after an accidental injury.
If the blood donated is incompatible with the patient’s blood group, it can trigger an unlikely immune response, platelet clumping, or blood agglutination, which can also be life-threatening.
In pregnant women, blood typing is of utmost importance. Suppose the mother is Rh-negative and the fetus is Rh-positive. In that case, Rh incompatibility occurs where the antibodies from the mother may damage the fetus's red blood cells via the bloodstream. In such cases, a drug called RhoGAM is given to the mother to prevent this event.
What Are the Risks of Blood Typing?
The blood is withdrawn from the person to evaluate it for blood typing. This procedure can pose minimal risk to the person like:
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Hematoma formation (bleeding under the skin).
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Infection at the site of injection.
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Profuse bleeding.
How to Prepare for a Blood Typing Test?
There is no special preparation required for blood typing. Hydrate yourself well with enough water. Have fruits and fresh juice in case you feel dizzy. Also, it is always better to accompany someone to the hospital.
How Is the Blood Typing Test Performed?
The blood typing test can be performed at a hospital or a pathological laboratory. The skin at the puncture site needs to be disinfected with an antiseptic before the test to prevent infection. A band will be wrapped around the arm by the operator to make the veins more prominent. A needle is inserted to draw the blood sample from the arm. Once the blood is withdrawn, a bandage will be placed over the injection site. A lab technician will mix the blood sample with the antibodies to determine the blood type. This mixing will trigger a reaction in type A and type B blood by the antibodies. The technician will then see how the antibodies react with the blood type.
If the blood cells are clumped together when mixed with antibodies against blood group A, the person has blood type A. The blood sample is then also combined with an anti-Rh serum. If there is a clumping of blood cells in response to the anti-Rh serum, it is suggestive of an Rh-positive blood group in an individual.
Based on the results obtained, the healthcare provider can determine the type of blood that can be safely received by the patient:
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If a person has type A blood, he can only receive blood from people having type A and O blood.
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If he has type B blood, he can receive blood from people having type B and O blood.
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If the patient has type AB blood, he will be able to receive blood from people having blood types A, B, AB, and O.
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If the person has type O blood, he can only receive blood type O.
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If the person is Rh+, he can receive either Rh+ or Rh- blood.
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If he is Rh-, he can only receive Rh- type blood.
What Is the Difference Between Blood Typing and Cross-Matching?
Many other antigens are present besides A, B, and Rh. The minor ones are not detected during the process of blood typing. If left undetected, an immune reaction may trigger while receiving certain blood, even if the A, B, and Rh antigens are matched. Therefore, blood typing is the test used to determine the blood type and Rh factor of a blood sample. Cross-matching involves identifying the best donor for a patient before surgery or blood transfusion.
Conclusion
Blood typing is a method to identify the blood type of a person. Blood typing is a very important test that should be done before performing any surgery or blood transfusion process. This test helps prevent any dangerous reaction during surgery that can be fatal at times.
