Immunofluorescence techniques in the investigation of a transfusion fatality due to ABO incompatibility

A 5-year-old girl died some minutes after starting to receive a transfusion of blood, without having previously typed her blood group or that of the donor, who were both supposedly of group 0. Blood groups were investigated in pharynx tissues taken 10 days after her death using the immunofluorescence technique and counter-staining with p-phenylenediamine. It was discovered that the girl was of blood group B and that the transfusion was of blood group A, hence a transfusion error as cause of death is proposed. A field of great medicolegal interest is opened by using immunofluorescent techniques in forensic pathology as an efficient complementary test when doing an autopsy on a person who died during a blood transfusion.