Stability of urine samples for sample identification : DNA-based typing Vs. steroid profile

We investigated and compared two strategies for the identification of urine samples in doping control taking into account the stability of samples at different temperatures. Four urine samples (2 males and 2 females) where divided into aliquots and stored at different temperatures (+37°C, +4°C, room temperature, -20°C) from t=0 (fresh sample collection) to t=25 days. Both the steroid profile and the DNA typing were analyzed and these two strategies of sample identification were compared. The results indicated that DNA-based typing allows a more reliable and suitable strategy for sample identification, also in those cases in which steroid profiles show high patterns of sample degradation.