My 'expert' opinion

I was stationed at the site that tested all Army urine drug samples for a little over 3 years and from my experience the B sample will have at least the same amount of the drug if not more. The Army does not have A and B samples. If there is a positive test in the Army, the same sample is tested to see how much of that specific drug is in the sample. The method used is mass spectroscopy which quantifies the specific drug by breaking it apart and quantifying the components. False positives occur so the first step is to retest the sample and then do the quantification if the retest is positive. I have seen a few false positive but no positives that were later found to be under the threshold to be positive in the first place. Different drugs have different thresholds to be positive. I am not familiar with ostarine. The common urine drug test contains about 9 drugs. The NCAA tests a lot more so sample A is testing, say 20 drugs; sample B is isolating 1. I just don't see the guys playing. Maybe they are exonerated but from what I know, I doubt it. Need to find the source to prevent the same situation in the future. They have many people on salary from nutritionist and strength coaches to tell the guys what they can and can't take.

Message was edited by: 98_00 Walkon®

cmb04

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Re: My 'expert' opinion

Dec 27, 2018, 6:58 PM

Posted from another site from a “lab guy”, so take it for what it’s worth. Thought it was interesting. Also note that Dex said the ostarine came back at 0.02
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On the purpose for the players' legal representation: "False positives don’t need anything to really go wrong. If the concentration detected was right around the method detection limit for ostarine, it could be a random positive bias blip that lasted for a few samples.
Wait a day or two and run sample B, & run sample A on another instrument."

"There’s a concentration range for ostarine that the instrument is routinely calibrated for. You can still totally see concentrations lower than that, and they are reported up to a really tiny number called the MDL (Method Detection Limit).
If it’s below the less than the lower calibration limit but more than the MDL, it’s reported but considered iffy. That’s probably why they called it a sliver and needed to run the duplicate sample."

"A and B are the same sample split up at collection time. Analytical chem instruments always have some noise in the baseline on the graphs, so there’s a lower concentration limit for detecting anything. You calibrate the instrument for a large range of concentrations but you can still see things below this range.
There’s a hard limit, though, called the MDL (method detection limit). Any hit below the MDL concentration is considered invalid and/or noise.
So if you get a positive hit for ostarine higher than the MDL but below your calibrated range for ostarine, you still call it a hit for ostarine but it’s statistical significance of that ostarine hit is considered low.
Then you either run it on another similar instrument for confirmation or you run a duplicate of the sample. Which is where we’re at now. You usually don’t tell the client about a positive A hit because you’ll get them all riled up for nothing if B comes back negative. Happens every day in a lab, though."

There’s two hard limits of detected concentrations in this sort of instrumentation: the lowest concentration of a known range of calibrated concentrations (5-500, so 5) and the method detection limit (MDL), which is the absolute lowest amount of ostarine you can report as a hit. The MDL is a statistically derived number, so it can be ridiculously low sometimes (like 0.05)
If they were getting ostarine hits somewhere between the normal calibration range of 5 to 500, they’d still test the B sample but I don’t think Dabo would call that a “sliver”. That’s a high-confidence hit.
If you get an ostarine hit below 5 but higher than 0.05 (MDL), you absolutely need duplicate sample confirmation and/or running A and B on another instrument. That’s what I’d call a sliver."

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Re: My 'expert' opinion

Re: My 'expert' opinion

this makes a lot more sense than all of the other experts

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