Blood Grouping (Types of Blood) – The ABO & RH System
Noble Laureate Karl Landsteiner was involved in the discovery of both the ABO blood group (in 1901) and RH blood group (in 1937). There are more than 20 genetically determined blood group systems known today, but the ABO and RH systems aer the most important ones used for blood transfusions. Not all blood groups are compatible with each other. Mixing incompatible blood groups leads to blood clumping or agglutinations, which is dangerous for individuals.
Each person’s blood is one of four major types: A, B, AB or O. Blood types are determined by the types of antigens on the blood cells. Antigens are proteins on the surface of blood cells that can cause a response from the immune system.
What is Rh factor? The Rh factor is a type of protein on the surface of red blood cells. Most people have the Rh factor – they are Rh-positive. Those who do not have the Rh factor are Rh-negative.
How does a person get the Rh factor? The Rh factor is inherited – passed down through parents’ genes to their children.