Difference Between Blood Types A,B,AB,O

What are the differences in blood types?

All the blood in the human body is immersed in a complex fluid mixture called plasma. The cells of the body are made up of 45% blood and 55% plasma. There are four types of human blood – A, B, AB, and O. The type of blood a person has depends on the chain of sugars that bond to the membrane lipids and proteins of the red blood cells. AB blood type is made up of both A and B gangliosides, and the determinants are short, branched chains of oligosaccharide. About 85% of the population has RH positive blood, which means it contains the rehsus factor. The remaining 15% have RH negative blood.

Blood Type A

Blood contains two agglutinogens, named A and B, that trigger the production of antibodies to kill or neutralize what they see as being foreign substances. They have complementary agglutinins in the plasma, named a and b. When a person has specific agglutinogens in the red blood cells, the complement does not exist in the plasma. Therefore, a person who has A agglutinogens in the red blood cells would not have a agglutinins in the plasma. The blood type would be A and if rhesus is present, it would be A+VE. If there is no rhesus, it would be A-VE.

Blood Type B

A person whose red blood cells contain the agglutinogen B does not have the corresponding b agglutinin in the plasma and therefore has type B blood. If there is rhesus present, it is B+VE and if there is no rhesus, it is B-VE.

Blood Type AB

The red blood cells contain both A and B agglutinogens and do not have any complementary agglutinins in the plasma. This is blood type AB and can be positive or negative depending on the presence of rehsus. A person with AB blood is considered a universal blood donor but can only give blood to those who have AB blood.

Blood Type O

Those with this blood type do not have either A or B agglutinogens, nor do they have the complementary a and b agglutinins in the plasma. Therefore the blood type is classified as 0 and can be O+VE or O-VE. This blood group is regarded as being universal and a person can donate blood to any of the blood types.

Blood type plays an important role in blood transfusion. A person must be given the blood suitable for his type. If not the results could be fatat.


  • Cara

    AB type blood is the universal recipient not the universal donor as stated here.