ABD PAD® allows the control of the ABO/Rh blood group (confirmation or pre-donation control), by determining the presence of the A, B and D erythrocyte antigens on the surface of human red blood cells.
 
PAD® devices use the M-TRAP® technology.

M-TRAP® is a patented proprietary technology. It allows, from a sample of blood, the detection of a reaction between an erythrocyte antigen and an antibody directed specifically against this antigen.

This technique is based on an immunoblotting test, using spots. The tested red blood cells, carrying an antigen, interact with the corresponding antibodies, revealing a red color spot. The red blood cells which do not carry the antigen, do not interact with the antibodies and cross the membrane. The spot will appear light green or white.