Simple DNA extraction of urine samples: Effects of storage temperature and storage time

Urine samples are commonly analysed in cases with suspected illicit drug consumption. In events of alleged sample mishandling, urine sample source identification may be necessary. A simple DNA extraction procedure suitable for STR typing of urine samples was established on the Promega Maxwell® 16 paramagnetic silica bead platform. A small sample volume of 1.7 mL was used. Samples were stored at room temperature, 4 °C and −20 °C for 100 days to investigate the influence of storage temperature and time on extracted DNA quantity and success rate of STR typing. Samples stored at room temperature exhibited a faster decline in DNA yield with time and lower typing success rates as compared to those at 4 °C and −20 °C. This trend can likely be attributed to DNA degradation. In conclusion, this study presents a quick and effective DNA extraction protocol from a small urine volume stored for up to 100 days at 4 °C and −20 °C.