Quote Originally Posted by Burnt Toast
Some things to keep in mind in the future:

- Even though their cutoff thresholds numerically differ, a 50 ng assay is functionally equivalent to the 15 ng GC/MS. Their cutoff thresholds numerically differ is because the assay recognizes all 31 metabolite concentrations combined, while the GC/MS recognizes only one metabolite concentration.

THC enters the body in its ingested form and exits the body as 31 different metabolite concentrations. The most prevalent of these concentrations is THC-COOH.

In order to test negative on the assay, the whole combination of the 31 metabolite concentrations must register below 50 ng.

In order to test negative on the GC/MS, only that one metabolite concentration (the THC-COOH metabolite concentration) must register below 15 ng.



- There is no meaning attributed to the intensity of a line on a home test or any other instant assay. Even synthetic urines (which contain no drug metabolites at all) can produce a faint line on an assay.

A faint line is still a negative. Even if an untrained tech were to misinterpret a faint line as a "non-negative", and sent the sample to the GC/MS for confirmation, the sample would still come back as a negative.
hey burnt toast are there 15 ng/ml assays that test for all 31?
nixon1990 Reviewed by nixon1990 on . Passing a Quest Diagnostics UA Drug Test This is my experience in passing a Quest Diagnostics UA Drug test for a UR Drug Screening 6405N SAP 550 GC/MS. I recently graduated from college and within about 5-6 weeks got a great job offer. I started smoking in college my sophomore year and after that first year I became a heavy user. Smoking everyday several times a day for about 3 years straight. I quit smoking after Christmas to prepare for the chance that I would be tested for a job. I took about 3 at home drug tests during this Rating: 5