Quantitative IgD measurement for discrimination of human bloodstains

The IgD concentrations of eluates of artificial bloodstains and of the corresponding sera from 40 subjects of different ages were measured by single radial immunodiffusion. IgD was found in bloodstains stored up to 53 days, i.e. IgD storage stability is sufficient for forensic purposes. Since serum IgD concentrations of individuals, in particular of adults, are almost invariable and serum levels of different individuals can vary by more than a 1000-fold, the discrimination of bloodstains on the basis of IgD is generally possible. Thus IgD constitutes a further marker in antibody profiling of bloodstains.