Application of ELISA-ABC method to the identification of minute human bloodstains.

Bloodstained threads (1 cm in length) were tested to identify human origin by a direct ELISA-ABC method using biotinylated antibody against human HbA0. By this method human bloodstains were clearly distinguishable from bloodstains of other species including Japanese monkey. The minimum detection limit of bloodstains prepared from undiluted human whole blood was 1:5, 120 (28 ng Hb) and that of bloodstains from diluted human whole blood was 1:640-1:1, 280. Human Hb was more easily detectable in bloodstains prepared from diluted human blood after extraction with 5% ammonia than after extraction with phosphate-buffered saline.