When an employer requests a drug test from an employee, the employee is instructed to go to a collection site. There, the employee’s urine is collected in a specially designed secure cup and sealed with a tamper resistant tape. The cup is then sent by express delivery service to a testing laboratory where it will be tested for several drugs. The first step at the testing site is to split the urine into two aliquots. One aliquot is first screened for drugs using an urine analyzer that performs immunoassay as the initial screen. If the urine screen is positive then another aliquot of the sample is used to confirm the findings by gas chromatography - mass spectroscopy (GC-MS) methodology. All test results are relayed to an MRO (Medical Review Office) where a medical physician reviews the resu