[Comparative studies on human blood identification from minute bloodstains by various methods].

In reports on human blood identification from bloodstains, the minimum detection limits obtained by various methods were hardly compared directly, because maintaining conditions of bloodstains tested are different from one another. The minimum detection limits of human blood from a minute bloodstain maintained under the same conditions were comparatively studied by transferred dot-ELISA, microprecipitation method, precipitation ring test, reversed passive hemagglutination test, latex agglutination test, colloidal gold agglutination test and sandwich ELISA. In the blood solution, the minimum detection limits obtained by the methods mentioned above were ranged from 1/16 x 10(6) to 1/16 x 10(3) diluted blood, and amounts of the minimum required Hb were from 1.1 ng to 133.8 ng. A cotton thread (1 cm in length) was besmeared with 1 microliter of diluted bloods, and 2 mm out of the blood-stained thread and several fibrils of the 2 mm thread were tested. In the test on a blood-stained thread passed for a week, the minimum detection limits were ranged from 1/5120 to 1/40 in dilution of the blood and 5.4 ng to 1260 ng in Hb amount. Transferred dot-ELISA was the most sensitive on detection of human blood in blood dilution and Hb amount, and precipitation ring test required much blood. The detection limits were ranged from 1/1280 to 1/5 in dilution and from 55 pg to 12 ng in Hb amount for the blood-stained fibrils passed for a week. Precipitation ring test and colloidal gold agglutination test gave a non-reaction. Transferred dot-ELISA was the most sensitive on human blood detection of a blood-stained thread and fibrils.