Laboratory Drug Testing – Urine

Post: Laboratory Drug Testing – Urine

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Last updated on February 26th, 2021 at 09:56 am

Most drug testing in the United States involves a laboratory receiving and testing urine, oral fluid, hair, or blood specimens. In this blog post we will talk about laboratory drug testing with a urine specimen and answer the question of what happens when a urine specimen goes to the lab for drug testing.

Drug Testing Process

The process involves parties including the specimen collector, laboratory, and medical review officer (MRO). The process for each of these parties will be reviewed here. The testing process can be initiated by any of the following (ordering parties) and often others:

  • Employers
  • Parents
  • Probation officers
  • Attorneys
  • Court systems
  • Child custody agencies
  • Self-directed (personal) tests

When ordering a test, the ordering party must specify what test they want the lab to perform. This test could be a five-panel test, a ten-panel test, or one of many others.

Specimen Collection of the Urine Sample for Drug Testing

Let us start with the basic process of how a urine specimen is tested for drugs. An employer or some other party orders the test and specifies the individual to be tested, i.e., the donor. The donor will then go to a facility called a collection site where their urine specimen is collected and prepared to be shipped to the laboratory. The laboratory and collection site are separate facilities in separate locations.

There are strict custody-and-control procedures with the use of a 5-part carbonless custody-and-control form (CCF) or the use of electronic collection on a computer system called e-CCF. The employer or other party ordering the test gives the donor an electronically produced order form (donor pass), an authorization form, or the actual 5-part carbonless CCF.

The urine specimen collected is sealed with a security seal containing a unique specimen ID number that will also be present on the paper or electronic CCF. The specimen is then shipped to the laboratory via FedEx, UPS, lab courier system, or any combination of these. Specimens picked up today will typically arrive to the lab very early the next morning.

What Happens at the Lab?

Each morning, the lab receives the specimens collected the previous day. Now is when the testing begins with an enzyme immunoassay (EIA) methodology often called an emit screen. This is the initial screening of the urine specimen. With this method of screening, the lab detects a binding reaction between the target drug and/or drug metabolite and an antibody producing a signal detected by automated instruments indicating whether the target compound might be present in the specimen. Basically, this screening determines if there is a substance belonging to a drug class in the urine specimen. This emit screen provides fast, efficient separation of negative specimens from those that require further testing called confirmation testing.

For specimens that have tested negative with EIA methodology, results are immediately reported to the MRO. After a few checks in the review-and-verification process, these are reported the same day to the ordering party (for example, the employer); the majority of the time, this should be a 1–2 business-day process.

Now if the specimen was positive on the emit screen, there must be further confirmation testing, which is usually done the next day. Either the gas chromatography–mass spectrometry (GC/MS) or liquid chromatography-mass spectrometry (LC/MS) methodology is used for confirmation testing. This testing is capable of specifically identifying and distinguishing the drug or drug metabolite from other compounds that might be present in the specimen. In addition, the lab can accurately measure the concentration of the drug metabolite found. If positive, the lab has determined the exact metabolite of a drug with the quantitative level of the metabolite of that drug, thus providing a final positive or negative result. This process ensures there are no false positives.

Final lab results can sometimes be invalid, adulterated, substituted, or rejected for testing. An invalid result is when the lab cannot provide a scientific and legally defensible result of either positive or negative. The other potential results are as follows:

  • Adulterated: The lab has determined that some substance was added to the urine specimen in an attempt to cheat the drug test. The MRO reports this  adulteration as a refusal to test.
  • Substituted: The lab has determined that the specimen provided is not urine. It is not consistent with normal human urine; something was provided other than human urine. The MRO reports this as a refusal to test.
  • Rejected for testing: The lab will not test the specimen for a variety of reasons. These reasons include:
    • The specimen leaked in transit
    • An insufficient quantity of urine was submitted
    • The lab’s copy of the CCF form was not included with specimen
    • The specimen ID numbers on the urine samples do not match the specimen ID numbers on the CCF form
    • The specimen security labels are ripped, torn, or appear to have been tampered with.  

When a specimen is rejected, the lab does no testing, and the MRO reports this rejected test as a canceled test.

Medical Review Officer (MRO) Positive Review

The MRO receives the positive or negative results of the confirmation testing. If negative, after a few checks in the review and verification process, the result is reported to the ordering party (for example, the employer). This process typically takes 2–3 business days.

If the lab result is positive after the confirmation process, the MRO’s process becomes more detailed. The donor is called and told of his or her positive result. The donor is asked about any medical explanation, perhaps a prescribed medication. The MRO, who is a licensed physician, then verifies the prescription with the pharmacy or prescribing physician. If the prescription information checks out, the result is reversed to negative and reported to the ordering party (for example, the employer). These results will take 3–4 business days but perhaps longer if the donor doesn’t take the MRO’s calls or does not return the MRO’ call after messages are left. It is important to note that when an MRO reviews a positive result received from the lab, the final outcome could be positive or negative.

How do I get my drug test results?

At National Drug Screening, we have an automated system with a web portal available to our ongoing customers. MRO-reviewed drug-test results are reported into the web portal and are also available via e-mail. For one-time testing situations, our individual clients receive results via e-mail.

Learn More About Our MRO Services

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More on Drug Testing at Quest Diagnostics

Laboratory Drug Testing – Urine

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