Frequently Asked Questions

I had my patient's urine collected and sent to two different laboratories for comparison. The first laboratory came back with a positive THC result, however your laboratory came back negative for THC. Explain this please.

Two different laboratories can have different methodologies, different sample preparation techniques, different cutoffs, different instrumentation, etc. THC is also a very sensitive compound that can break down rapidly in urine over time and temperature changes. In addition, although the result may state Negative it does not mean there was no THC present, it may mean that the THC concentration may not have been high enough to trigger a Positive result but it still is present. Different THC cut-off levels between labs could explain this as well.