when I took my dot drug test they gave me what's called the long form and on the back of it they wrote if I had blood in my piss or some other medical problems.When I asked how they could tell if their was something wrong on the spot like that she said remember that strip I dipped in the cup that's what it's for. then I said to her [I was kinda fishing around at this point]I thought it was the actual drug test and she goes no we send those to a lab. and that was probably what the strip in your case was for as well.