Detectability of group-specific component (Gc) in aged bloodstains.

An improved method of group-specific component (Gc) typing was conducted electrophoretically on agarose gel. Individual bloodstains randomly collected from different individual donors over a five-year period at intervals of approximately one month were checked for Gc activity. Group-specific component was typed accurately in dried bloodstains stored at room temperature up to 43 months in age. From 100 different donors, bloodstains ranging in age from 38 to 43 months were tested by the methods described and 73% of the samples were interpretable for Gc.