The principle of this method is based on the magnetization of red blood cells: E.M.® Technology. This principle uses the Indirect Antiglobulin Test (IAT) in solid phase combined to magnetic field. This test is performed when looking for the following antigens: Fya (FY1), Fyb (FY2), Jka (JK1), Jkb (JK2), S (MNS3), s (MNS4) .