Just read that the cut-off level for this test is 50 ng/ml. Is that the norm for what doctors go by for employment?
For non-DOT situations, its the party paying for the test who determines what the cutoff level should be, not the labs. The lab just provides the "test menu" for the client to pick and choose from. To answer your question, a 50 ng Immunoassay is pretty much standard fare. It is mandatory on all DOT tests.