Abstract
In this study, to apply immunohistochemical staining to the ABO blood grouping of non-medullated hair samples, the blocking condition and chromogenic substrate of the current protocol were modified. When 3,3',5,5'-tetramethylbenzidine was used as a substrate, the cortex of the longitudinally sectioned non-medullated scalp hair was positively stained parallel to the hair fiber; however, non-specific staining were shown in the medullae of medullated scalp hair. Non-specific staining was improved when blocking was performed using 10% normal rabbit serum at 37°C for 1 h. In the blind trial, the ABO blood group of all medullated and non-medullated scalp hair was successfully determined by immunohistochemical staining modified in this study. The biotin-conjugated ulex europaeus I suitable for this method was also validated. In conclusion, it is thought that ABO blood grouping of hair samples using this modified protocol of immunohistochemical staining is useful for screening hair samples before DNA analysis.
