Blood Grouping and Rh Typing

Blood group test is done to determine your blood group which is important for blood transfusions and blood or organ donations.  
ABO system is based on the presence or absence of specific antigen A, B on the surface of RBC. O means that neither A nor B antigen was found on RBC. If the antigen is absesent then body then makes antibodies against that antigen i.e., antibody A, antibody B. Apart from this, the blood is also tested for the presence or absence of a protein known as rhesus factor (Rh factor) on the surface. As per the ABO blood group is classified into 4 broad types ( type A, B, AB and O). Based on this, it is decided from whom can we receive blood and donate blood to. 

The 4 major blood types of the ABO typing systems are:

• Type A
• Type B
• Type AB
• Type O

The Rh or the Rhesus factor is a type of protein/antigen found on the surface of your RBCs. In the presence of this protein, the blood is typed as Rh positive and if the protein is absent, then the blood type is called Rh positive or Rh negative. This factor is also inherited from parents and a baby can inherit this protein from either of the parents.

The Rh-positive blood group is more common than the Rh-negative blood group. Having an Rh-negative blood type may not affect the overall health of a person but can affect pregnancy. In case the expecting mother is Rh-negative and the baby is Rh-positive, there could be an Rh incompatibility which needs to be discussed with the doctor immediately.

Why Is Blood Typing Done?

Blood typing is done to determine the type of blood group a person has. This may be essential in situations:

• When someone requires organ transplantation or blood transfusion, it is important to know the blood compatibility of the donor and recipient
• When a woman is pregnant, it is important to check the compatibility of the mother's and fetus' blood
• When someone is donating blood, knowing blood compatibility is again essential
• When newborn babies need to be tested for certain diseases