DNA typing of human dandruff

Dandruff particles contain a considerable portion of nucleated cells within the aggregates of nuclei-free corneocytes. The nuclei could be partially degraded due to epidermal differentiation processes. To test the suitability of DNA from dandruff for forensic application, a study of 35 subjects and two crime cases has been carried out using different STR polymorphisms. In 90% of the samples DNA genotyping could be easily performed indicating that DNA from dandruff is at least suitable for STR analysis. DNA quantity per dandruff particle varies extremely within a range from 0.8 to 16.6 ng DNA for the tested subjects. Genotyping was also possible for a single dandruff particle if DNA extraction volume had been reduced. In mixed samples from dandruff coextracted with bloodstains or semen stains dandruff genotype was detectable. in some cases. These results demonstrate the relevance of dandruff in forensic casework either as an additional sample or as a source of inadvertent contamination.