ABO blood grouping of hairs using an avidin-biotin-peroxidase complex technique.

Fifty-nine hair specimens obtained from human autopsies and volunteers were used for the determination of ABO blood group substances using the ABC (Avidin-Biotin Complex) technique. Positive staining for A, B and H blood group substances was detected only in the medulla of the hairs. Blood group antigens could not be detected in seven hair specimens because they possessed no medulla. Forty-seven specimens obtained from fresh cadavers and volunteers gave the correct results corresponding to the blood group of the donor, but some specimens from individuals of blood group A2, Le(a + b-) showed weak reaction with anti-A and strong reaction with anti-H. The staining intensity with anti-B and -H in some individuals of blood group AB was stronger than with anti-A serum. Five hair specimens obtained from decomposed bodies were also examined. The blood group antigens could be specifically detected in hairs obtained from two exhumed and one putrid body, but no positive reactions were obtained from two cases of drowning where the bodies had been in the sea for about 6 months. In a blind trial, hair specimens from 28 individuals were also examined. Twenty-two specimens which possessed a medulla gave the correct result. Six specimens gave no result because they possessed no medulla.