Quote Originally Posted by cody2kz28
ps still been reading up on drug test just becuase im interested now and ran across something that is saying probation uses a 15ng cut off if so verusus the 50ng cut off from walgreens will i be ok even if i passed the one early today or should i still worry for the next few days??
Dont let the lower cutoff thresholds worry you.

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

THC enters the body in its ingested form and exits the body as 31 different metabolite concentrations, the most prevalent form being the THC-COOH concentration.
In order to test negative on the assay, the whole combination of all 31 metabolite concentrations must register below 50 ng.
In order to test negative on the GC/MS, only one metabolite concentration, THC-COOH, must register below 15 ng.

It must be understood that when a urine sample tests negative on the initial assay screen, the testing process is finished at that point as a "pass" - no confirmation GC/MS will be performed. Due to its high cost, the GC/MS is only performed on the drug(s) that tested positive on the initial screen.