Species-specific determination in a horse urine sample from a positive doping case

S. DÍAZ, M. KIENAST, E. VILLEGAS-CASTAGNASSO, N. PENA, M. MANGANARE, D. POSIK, P. PERAL-GARCÍA AND G. GIOVAMBATTISTA.

JOURNAL OF FORENSIC SCIENCES

Año: 2007

0022-1198

: In order to detect switching and/or manipulation of samples, the owner of a stallion asked our lab to perform a DNA test on a positive doping urine sample. The objective was to compare the urine DNA profile versus blood and hair DNA profiles from the same stallion. Ten microsatellite markers were investigated to establish the horse urine identity, but no PCR results were obtained for horse-specific markers. In order to determine the species origin of this sample we analysed the mitochondrial Cytochrome b gene. The analysis of blood and hair samples produced reproducible and clear PCR-RFLP patterns and a DNA sequence match with those expected for horse, but the urine sample results were consistent with human DNA. These results allowed us to exclude stallion as the source of the urine sample and to demonstrate its human origin, confirming that urine sample have been manipulated.