Abstract
To date, the absorption-elution test has been widely used for ABO blood grouping of bloodstains, hairs, nails, and teeth. Bloodstains found at a criminal scene are often diluted and hemolyzed with water. Few papers dealing with the accuracy of the absorption-elution test in such stains have been published. In this study, a semiquantitative analysis of the absorption-elution test was performed using bloodstains made by dropping whole blood and blood dilute with various solvents onto filter papers, cotton, silk, nylon, polyester, polyestercotton, linen, wool, and rayon. When blood samples obtained from 30 different (group A: 10, group B: 10, group AB: 10) adults were diluted with normal saline or distilled water and dropped onto filter papers, detection limits of group A antigen for the absorption-elution test were 8-fold or 16-fold dilution with either solvent; those of group B antigen, 16-fold or 32-fold. When the same blood (group A, B, AB: leach) was diluted with normal saline or distilled water and dropped onto various materials, detection limits of group A antigen for the test were 4-fold or 8-fold dilution with either solvent for all 9 materials; those of group B, 16-fold or 32-fold dilution. When the same blood (group A, B, AB: leach) was diluted with various solvents and dropped onto filter papers, detection limits of group A antigen for the test were 4-fold or 8-fold dilution with all 9 solvents; those of group B, 16-fold or 32-fold dilution. The use of papain-treated red cells instead of non-treated cells improved the detection limit of group A antigen for the absorption-elution test into 32-fold dilution with normal saline and improved the detection limit of group B antigen into 64-fold dilution. When bloodstains were stored for up to 6 months under indirect illumination at room temperature, the detection limits of group A antigen for the test decreased to 2-fold dilution with the saline 6 months after storage; those of group B antigen, to 4-fold dilution.
