In medical situations in movies and on television, someone often calls out "Type and cross for 2 units STAT!". It is the medical lab scientists in the blood bank or transfusion services laboratory that perform the lab testing (blood typing and crossmatching, a “type and cross”) necessary when someone needs a blood transfusion. All health care professionals have patients’ lives in their hands, but blood bankers have to be exceptionally skilled and able to keep their cool in emergency situations. Transfusing the wrong type of blood can kill someone!
You or someone you know probably has given blood at your local blood bank. Blood donor centers screen donors to be sure they are healthy, collect units of blood and then test the donor blood to be sure it is as safe as possible. Single units of blood can be split into components such as platelets, plasma, and cells to stretch that unit as far as it can go. After that, blood is shipped to hospitals where it is needed.
In the field of medical laboratory science, people commonly call this discipline "blood banking." The field has also been referred to as immunohematology in that people working in transfusion services are experts in immunology and hematology (the study of blood) as they relate to providing blood components to patients whose lives may depend upon them. Blood bankers also know a great deal about genetics since your genes determine your blood type and the way your body will react against blood that is foreign to you. Although DNA testing is used now, blood types can be used on blood found at crime scenes or in paternity testing. Transfusion services is an interesting place to work, and you have the satisfaction of knowing that you helped save someone’s life.