A universal donor is someone who can donate to any patient regardless of their blood type.
People with an O blood type are usually referred to as universal blood donors; however, people with an O-(negative) blood type are the actual universal donors.
Reason for O-(Negative) is a universal Donor
The reason for this is that their red blood cells would not carry antigen. As a result, they are able to donate blood to any blood group. A user with blood group O+ (positive cells) cannot donate blood to someone with Rh-negative blood.
There are 38 human blood group systems recognised by the International Society of Blood Transfusion (ISBT). The ABO and Rh systems are the most commonly used of these 38 systems.
What Factors Influence Blood Type?
Blood types are determined by the lack or presence of certain antigens. An antigen is any molecule that causes your immune system to create antibodies in order to combat it. A&B determines the four major blood groups based on whether the surface of your RBCs (Red Blood Cells) contains or does not have the two antigens.
Furthermore, whether or not the Rh factor, a protein, is present affects whether your blood group is negative or positive. So, in total, there are eight universally recognised blood groups: A+ve, A-ve, B+ve, B-ve, O+ve, O-ve AB+ve, and AB-ve.
What is Rh Factor?
Rh, which stands for Rhesus system, contains 49 blood group antigens, the most important of which are five. The D antigen is the most important Rh antigen because it is the most likely of the five basic Rh antigens to elicit an immune system response.
If RhD is present, the blood group is referred to as RhD+ (positive), and if it is not present, it is referred to as RhD- (negative). As previously stated, the O- blood type can be safely given to anyone with any blood type since it lacks any A, B, or RhD antigens on the surface of the red blood cells. As a result, it is compatible with all other ABO and Rh blood groups.
How to declare Blood type as Universal Donors?
The blood type, also known as the blood group, is a sort of blood classification based on the presence or absence of antibodies and inherited antigens on the surface of red blood cells.
In our blood, there are red blood cells, white blood cells, and platelets suspended in a liquid called plasma.
Antigens are protein and carbohydrate molecules found on the surfaces of red blood cells. Antibodies are protein molecules found in plasma called Immunoglobulins (Ig). Antibodies bind to the matching antigen on red blood cells in a specific manner. Antibodies are our natural defensive mechanisms that are created by the immune system in response to antigen exposure.
A persons with type O negative blood are universal red cell donors, while those with type AB blood are universal plasma donors.
Here we can see O+ is not a Universal blood donor.
O-ve is universal because it can be given to anyone. People with O- blood are known as universal donors because their blood can be given to any other person without fear of rejection.
O-ve is one of rarest blood type and comparing to this blood group have you heard or read about the blood group known as Rare of the Rarest? Which is only discovered with tremendous difficulty. This is not O negative, yet it is referred to be Bombay Blood
The O- blood type has the most diversity of all the blood types. The ABO system was created to help doctors figure out what type of blood to give patients who have lost a lot of blood.