Monday, March 29, 2010

Urine DNA profiling

Scientists will soon be able to use DNA profiling techniques to confirm the identity of racehorses that have tested positive to drugs.

Such a test would dispel any doubt about sample substitution and confirm that a sample did in fact come from a particular horse, helping to either confirm the identity of horses returning positive drug samples, or exonerating horse and trainer.

The report “DNA Profiling of Horse Urine Samples to Confirm Donor Identity” resulted from studies carried out by Paula Hawthorne and colleagues at the University of Queensland, and was funded by the Australian Government's Rural Industries Research and Development Corporation (RIRDC). The research team tested various techniques for DNA profiling on seven urine samples and compared the results with those from hair samples taken from the same horses.

They found that storage time and temperature had a significant effect on the success of the DNA profiling. Urine could be stored at 4°C for no more than two days (or frozen at -20°C or -80°C) before processing. Samples stored at 4°C for a week or more yielded no profiles.

The most successful technique, a commercially available test, allowed them to identify all twelve microsatellites, in four urine samples - all from male animals. As only seven samples were examined overall, it was not possible to tell whether that was a coincidence, or whether it really is more difficult to extract DNA from mare’s urine.

All DNA profiles from the urine samples matched those from the hair taken from the same horses.

There is still more work to do - for example, the researchers point out that drugs in the urine may interfere with DNA profiling. So once the best method of DNA profiling has been established, further tests will be required to assess whether the results are affected by drugs likely to be found in the urine.

However, the authors of the report suggest that once the optimum method has been finalised it should not take long to integrate it into existing procedures of racing drug-testing laboratories.

The full report is available for purchase or free download. See:

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