Specimen

Overview

Deciding on the appropriate specimen(s) to incorporate into a testing program is just as important as the selection of the testing technology.  Urine, breath, blood, sweat, hair, and saliva are the most common specimens and each is appropriate for different testing situations.

	Immunoassay (Analyzer-based)	Instant + POC	GC/MS & LC/MS	Detection Window
Urine
Blood
Sweat
Hair
Saliva

Urine

Urine is currently the most common specimen due to the relative ease of collection, lower test costs and complexity, higher metabolite levels, and longer detection windows.  The proper collection protocols are critical for urine testing as the donor must not have any opportunity to substitute, adulterate, or contaminate the sample.  It is also critical to test the quality of each urine sample (e.g., pH, temperature, creatinine).  With detection window of three to five days and noninvasive collection process, urine is an ideal specimen for programs that require frequent and random testing of their participants.

Breath

Breath tests are easy to conduct and offer results immediately, but are limited to testing for alcohol and best used in conjunction with another test specimen.  Alcohol use registers immediately on a breath alcohol test, but will typically only register for a matter of hours after use.  Breath is not included on the table above as it is completed using a specific handheld device.

Blood

Blood tests are highly accurate and offer no opportunity for sample adulteration or substitution.  However, the tests must be completed by a certified medical practitioner and entail a more complex testing process; both of which make blood tests the most expensive testing alternative.  While blood tests are a good alternative to detect if someone is currently intoxicated, the detection windows are generally too short to rely on for prior use beyond a one to two days.   Blood tests are also not a preferred option for programs that require frequent testing of their participants due to the invasive nature of the collection process.

Sweat

Sweat tests typically involve a patch that is worn by the donor for a specified period of time.  The patch absorbs the donor’s sweat during this period, which may contain detectable traces of drugs of abuse.  The patches are easy to apply and can provide information on drug use during the period the patch is worn by the donor.  Detection windows prior or beyond the period in which the patch is worn are limited.  The level of drug metabolites are generally not as high in sweat as they are in urine and studies have shown that the patch can be susceptible to external contaminants.

Hair

Drug use makes its way through the bloodstream and the drug molecules or metabolites are ultimately embedded within the hair shaft.  Approximately 50 to 100 strands of hair (from any part of the body) are analyzed to detect and identify any drug metabolites in the hair sample.  Hair tests are considered to be accurate and have detection windows up to 90 days.  Since the evidence of drug use is inside the hair, the test is not as susceptible to external adulterants (e.g., special shampoos).  However, hair is one of the most expensive specimens to test and it normally takes up to a week after use to detect the metabolites.  Hair tests are generally a good alternative for lower volume or frequency testing programs where a longer detection period is required.

Saliva

Saliva tests have increased in popularity in recent years primarily due to the ease of collection.  A single collector can take a sample from any donor, anywhere.  Drug use can be detected in saliva within a few hours after ingestion, which makes saliva a viable alternative for testing if someone is currently under the influence.  However, there is a wide variation in the quality and accuracy of saliva tests and the entire technology category is less proven than other specimen categories.  Some of the shortcomings of saliva testing include shorter detection windows and potentially lower metabolite levels for certain drugs, difficultly collecting enough saliva for both preliminary and confirmation testing, food and other contaminants that require additional sample processing or impact the detection of drug metabolites, and the current cost of the available tests.