Frequently Asked Questions

How do I sign my practice up for CTR's services?

Refer to the contact page or call 240-397-7060.

When can I expect to see my results?

Urine screening results via EIA are usually available within 24 hours upon delivery to the lab. LC/MS confirmation results will be available within 72 hours upon delivery to the lab. 

How long can the urine specimen stay at room temperature after collection?

We recommend that a sample be sent in within 72 hours of collection. We will accept specimens after this period, but please be advised that specimens will degrade over time and this could affect the detectability of certain drugs. If specimens cannot be shipped within that time period, you may refrigerate the sample for up to 7 days. 

How much urine is needed to perform a comprehensive panel?


Why is there a temperature strip on my collection cup?

Under normal situations fresh urine will display a temperature between 90 and 100 degrees. Specimens with a temperature out of range may indicate a substituted or adulterated sample.

Can I receive a pending report?

Pending reports will be available via the web portal. For example, a pending report may show screen results, but incomplete confirmation results will be displayed as "pending."

How are reports delivered?

The best way to recieve reports is through the web portal, but fax and email through our HIPAA compliant vehicles are also available. 

Why are some results positive on my report, but not highlighted red?

Results are only highlighted red when they are inconsistent with the prescribed medications. This is true for both positive and negative results. 

What does "cutoff" mean on my reports?

Cutoffs are the lowest measurable levels of concentration in which a compound is detectable in the specimen. These levels are specific to each drug and determined by CTR's team.

Why is my screen result positive, but my LC/MS result negative?

Screens use antibodies to detect the presence of a wide range of drugs, whereas, confirmation analysis looks for a specific compound. Furthermore, although very selective, screens can cross-react with structurally similar compounds and give a false positive. Confirmation testing is not subject to this cross-reactivity.

Why are some prescribed medications missing under “Prescribed Medications” on the lab report?

If a prescribed medication was not listed on your patient’s lab report, that typically means it wasn’t selected on the patient requisition form that accompanied the sample.

What does qns mean?

This means Quantity Not Sufficient. The volume of the submitted specimen is not enough to complete the ordered test or tests. 

How long can drugs be detected in the system?

Our in-depth Drug Information Material breaks down the retention times for a wide range of drugs. Here you can find information about specific drugs and their detection times. Click Here to view the Druge Detection Time Window Chart. 

Do you do oral fluid testing?

We are currently developing an oral fluid testing program. There are some downsides to consider when choosing oral collection vs urine. 

What are the disadvantages of oral fluid testing?

The disadvantage is that antibodies in most commercially available immunoassay drug screen tests, including ours, target metabolites. Metabolites are not found in oral fluid. In addition, drugs that are ingested orally (like ethanol) as well as those that can be smoked (i.e., methamphetamine, PCP, marijuana, and cocaine) may be detected in high concentrations in oral fluid following recent use due to residual drugs remaining in the oral cavity. However, under these circumstances, results may not be accurate because the drug concentration found in the oral fluid may not reflect the blood-drug concentration. 

I'm out of supplies. How do I get more?

Refer to the "Order Supplies" page on this website and fill out the required fields. Supplies typically arrive within 2-3 business days.