Most of the earliest blood transfusions, which occurred in the 1660’s, were performed on animals by Richard Lower. Karl Landsteiner discovered the blood types A, B, and O while experimenting with goats. Reuben Ottenberg performed the first successful blood transfusion in 1907.
According to the American Red Cross, there are currently eight known blood types, but only four of those are the main blood types. Those four include type A, type B, type AB, and type O blood. Type A blood can only be donated to someone with type A and/or type AB blood, type B blood can only be donated to someone with type B blood and/or type AB blood, type AB blood can only be donated to someone with AB blood, and type O blood can be donated to any blood type.
In the US, 39% of people have O Rh positive blood, 9% have O Rh negative blood, 31% have A Rh positive blood, 6% have A Rh negative blood, 9% have B Rh positive blood, 2% have B Rh negative blood, 3% have AB Rh positive blood, and 1% have B Rh negative blood.
To find your blood type, a test called the ABO typing test is performed. During this test, a sample of your blood is mixed A and B antibodies to see if any of the blood cells stick together. The reactive blood cells will stick together. Then, the liquid part of your blood is mixed with type A and B blood to determine which of your antibodies match the other blood’s antibodies.
The crossmatching test is used to identify any issues with your blood and the blood or organs of a donor. These tests are usually performed before blood transfusions, organ transplants, and major medical procedures. After the test, if your blood clumps up after being mixed with a donor sample, the blood is not compatible.
People with O negative blood have “universal” cells, meaning they can donate to any person with any blood type. Only 6.6% of the population had negative O blood. O negative blood is also the best for premature babies.
According to Dr. Peter DAdamo, whenever you eat, a chemical reaction occurs with the food and your blood therefore, you should train yourself to eat according to your blood type for cell protection. People with type O blood should eat mostly meats. Type A people should have close to a vegetarian budget. Type B people should have a "balanced omnivore" diet. Type AB people have the least strict diet. This diet is a mix of all of the other diets.
Japan has been using blood types to categorize people for years. For example, during WWII, Japan categorized their battle soldiers by blood types. Currently, kindergarten students in Japan are separated by blood types.