The antibody screening test that is done along with pretransfusion blood typing is used to ensure that the recipient
does not have a previously undetected bacterial or viral infection.
is not immunocompromised.
actually does have the blood type stated in the online chart.
is not making antibodies against antigens outside the abo or rh systems.

is not making antibodies against antigens outside the ABO or Rh systems.

Explanation:

Red blood cells have many protein and carbohydrates antigens on its surface , there are about 600 antigens , which are further divided into 20 blood groups .

The presence or absence of antigens determines the type of blood which can be given in the case of blood transfusion .  

Anti - A and Anti - B are the only naturally occuring RBC antibodies in the normal human plasma or serum . Others are classified as alloantibodies and autoantibodies .