Endogenous and exogenous erythropoietin (EPO) present in urine can be distinguished according to their isoelectric profiles. This methodology requires urine samples to be concentrated about 200 to 1000 times with manipulations that should remove most of the cells occurring in the original sample. In this study, we tried to obtain DNA profiles from 10 ultrafiltered urines (retentates) in order to evaluate whether a formal genetic identification was technically feasible. No nuclear DNA profiles could be established from retentates, despite 34 PCR-cycles amplifications. Contrastingly, mitochondrial DNA (mtDNA) profiles were obtained for 9 out of the 10 retentates. Apart from some particularities, retentate mtDNA profiles were all distinct and matched mtDNA profiles of corresponding reference samples.