The blood group from the observation is O negative.
The blood groups can be determined practically with the help of anti-serums.
One of the groups into which people or their blood can be classified based on the presence or absence of particular antigens in the blood (such as those labelled A, B, AB, or O) is called as blood group.
There are 4 main blood groups (types of blood) – A, B, AB and O.
Red blood cells, white blood cells, and platelets are contained in a fluid called plasma, which is the blood. Antibodies and antigens found in the blood help identify your blood group.
Plasma contains proteins called antibodies. They are a component of your body's built-in defenses. They identify alien objects, like bacteria, and notify your immune system, which then eliminates them.
Protein molecules called antigens can be detected on the outer layer of red blood cells.
The ABO system distinguishes 4 major blood types:
- Red blood cells with blood group A antigens have anti-B antibodies in their plasma.
- B antigens and anti-A antibodies are present in the plasma in blood group B.
- Blood group O - has both anti-A and anti-B antibodies in the plasma but no antigens.
- A and B antigens are present in blood group AB, however there are no antibodies.
So, as the question tells that Sara's blood doesn't coagulate with anti serum a, b and rh this means that her RBCs have none of the proteins on its surface leading to Blood group O negative.
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