Utility of results?
​To answer this question, we need to ask three questions:
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What molecule is detected?
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Sensitivity: What amount of a specific molecule can be in a sample to give a positive or negative result?
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The utility of the result?
Which molecule is detected?
The utility of the result?
​​ Saliva tests for the presence of the intoxicating THC molecule. Saliva samples are suitable for calculating the risk of a negative result in police tests during routine checks.
Urine samples test for the non-intoxicating metabolite THCCOOH. It is a molecule that is a result of the combustion of THC in the body. When THCCOOH is detected in urine, it is known that the body has recently burned THC.
What is the implications of a positive test?
What is the implications of a negative test?
Sensitivity is the test's limit for how much of a given molecule is needed to give a positive result.
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The saliva test in the webshop is a practical example. It has a sensitivity of 25 ng/ml.
* A positive test means that an amount of more than 25 ng THC per 1 ml of saliva has been detected. As much as 10,000 ng THC has been detected in 1 ml of saliva.
* A negative test means that there is less than 25 ng THC per ml of saliva.​ That is, from 0-24 ng THC per 1 ml of saliva.​
​An illustration of the propositions:
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If we assume that 1 ml of saliva (99% water) weighs 1 gram, then we can say that 10,000 ng of THC per 1 ml of saliva is the same as:
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0.00001g of THC per 1 g of saliva. = 0.001% THC in the saliva at the time of sampling.
Practical interprentations of saliva tests
​A positive saliva test means that you will provide a positive saliva test if you are stopped in a routine police check.
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A negative saliva test means that you have not detected as much as 25 ng THC per ml of saliva. Police tests can detect as little as 5 ng THC per liter of saliva. It is therefore recommended to ensure that you have a negative saliva test the night before driving.
Practical interpretation of urine tests
​A negative urine test with a sensitivity of 25 ng/ml means that there may be 0-24 ng THCCOOH per 1 ml of urine. This is an indication that the body has had relatively little THC to metabolize in the time before the test and that it theoretically should be little to no THC left in the blood.
A positive urine test with a sensitivity of 100 ng/ml must be interpreted as that the body has metabolized relatively much THC recently, and should be assumed a risk for illegal blood levels of THC
