[The immunohistochemical picture in transfusion of incompatible blood]

To provide evidence of transfusion of incompatible blood in the ABO system in forensic medicine also antigens A and B of the donor must be detected in the body of the recipient. The author presents his own experience with evidence of incompatible red blood cells with group properties A, B or AB by the indirect immunoperoxidase method in paraffin section of the recipient's tissues. A positive reaction makes it possible to detect also occasional incompatible erythrocytes in particular in the periphery. An advantage is in particular the high sensitivity of the method, and as paraffin tissue blocks are used, also the possibility of retrospective evaluation.