Blood donation and will screen for antibodies to less common antigens. More testing, including a crossmatch, is usually done before a transfusion. Type O negative is often cited as the "universal donor" but this only refers to red cell and whole blood transfusions. For plasma and platelet transfusions the system is reversed: AB positive is the universal platelet donor type while both AB positive and AB negative are universal plasma donor types. Most blood is tested for diseases, including some STDs. The tests used are high-sensitivity screening tests and no actual diagnosis is made. Some of the test results are later found
Blood type personality theory Blood type personality theory A pseudoscientific belief exists in some East Asian countries, that a person's ABO blood type is predictive of a person's personality, temperament, and compatibility with others. This superstition is similar to how astrological signs are perceived as influencing factors in a person's life in other countries. One of the reasons Japan developed the blood type personality indicator theory was in reaction against ethnic stereotypes coming from Europe. The popular belief originates with publications by Masahiko Nomi in the 1970s. The scientific community generally dismisses blood type personality theories as a superstition or pseudoscience because of lack