Persons with type O blood cells can serve as donors for all four 

 blood types, since the injected O cells will not be agglutinated by 

 the serum of any of the four blood types. Type O individuals, 

 therefore, are called universal donors. Since type AB persons 

 possess neither alpha nor beta antibodies in their blood serum, 

 such individuals can receive blood from any of the four blood 

 groups, and they are designated as universal recipients. While 

 it is generally advantageous to transfuse homologous (same type) 

 blood into a patient, the practice of employing universal donors 

 has proven safe and effective in tens of thousands of blood trans- 

 fusions performed both in civilian and in military hospitals. 



The question is often asked, is it not dangerous to inject blood 

 containing antibodies for the recipients' cells? The relatively few 

 isoantibodies administered in a transfusion wit^^h universal blood 

 are diluted about twelve to one by the rapidly circulating blood 

 of the recipient, and only minor clumping of red cells occurs. Ap- 

 proximately 1 or 2% of individuals administered type O blood will 

 respond with a slight elevation in temperature— a transfusion re- 

 action—but this is not considered serious. It is desirable to avoid 

 these reactions in patients who are critically ill, and that is the 

 reason for injecting homologous blood if it is available. 



TYPING OF BLOOD 



Preliminary to blood transfusions it is imperative that the blood 



be typed to determine compatibility. Two relatively simple 



agglutination procedures are available— the rapid slide test and the 



test tube technic. To perform the test one must have either A 



