Quote Originally Posted by Close2out
Fellow smokers,

I've been trying to search the forum for a bit of clarification. Does a gc/ms confirmation re-test all substances or just those that failed initial ua?
Only the panel(s) that have tested "non-negative" on the initial assay screen. So any drug panels that are negative on the initial, will not see the GC/MS. It would be too costly for both the lab and client to run the GC/MS on any panels that tested negative on the initial screen.

And if youre worried about the GC/MS because of its numerically lower cutoff threshold, dont be. Even though their cutoffs numerically differ, a 50 ng assay screen is functionally equivalent to the 15 ng GC/MS. For more info, do an Advanced Search of Posts with the terms "tests functionally equivalent".