Many ask how the basic urine tests work. To put it simply: an enzyme is added to your urine sample that binds with the metabolites of any drugs that may be present. Note the reagent does not bind with the drug but with what is eliminated by your system after metabolism. After a second reagent is added, a machine measures the activity in your sample. NuKlear blocks the binding mechanism resulting in a negative test. Please note that NuKlear is designed for the commonly used EMIT (basic urine test). If you are being administered the instant drug screen or “dip stick” test use the powdered urine or the less reliable dilution method – more info on this at nodrugwar.org.