To view the PEth Testing Panels and Collection Instructions, click here.
Direct Alcohol Biomarkers – EtG and PEth Webinar
Direct Biomarkers of Alcohol Use by Dr. Adam Negrusz
USDTL Urine Research
Urine Poster Presentations
USDTL Assisted Urine Research
Foundational Urine Research
Urinary ethyl glucuronide (EtG) and ethyl sulphate (EtS) assessment: valuable tools to improve verification of abstention in alcohol-dependent patients during in-patient treatment and at follow-ups 01-Jun-2009
Urine White Papers
New data from researchers at USDTL shows that propofol use can be detected in urine samples for as long as 28 days following low-dose anesthesia.
Effective July 18, 2016, USDTL will be implementing a new way of reporting quantitative results. In order to satisfy accreditation requirement, the concentrations of drugs exceeding the Upper Limit of Quantification (ULOQ) for any given drug will be reported as > ULOQ (greater than ULOQ). The ULOQ will be provided.
Quantity Not Sufficient (QNS) is a result of not having a sufficient quantity (volume) of specimen to test for the panels ordered. The amount of specimen required for collection is directly related to the amount of specimen needed to screen and confirm for the panels we offer. The initial screening uses a portion of the original specimen and the confirmation testing uses another portion of the original specimen. To forensically confirm positives, means running a new test, with a new portion of the original specimen, using a different analytical technique.
We are writing to notify our clients that effective February 1, 2016, we will no longer be testing urine for antihistamines and OTC amphetamines. We apologize for any inconvenience this may cause.
I am pleased to inform you that USDTL has succeeded in improving our urine assay for antihistamine drugs by reducing the cutoff from 500 ng/mL to 100 ng/mL. The improved urine assay for antihistamine drugs will be available starting August 3, 2015.
It is our first priority to deliver testing results that provide the most valuable information possible for your substance abuse testing needs. To better accomplish this duty to our clients, we are updating our policy concerning specimens that do not have sufficient volume for both preliminary testing and confirmation. Effective April 1, 2015, confirmatory tests that cannot be completed due to insufficient specimen volume will be canceled on an individual drug class and/or analyte basis. We will report confirmation results for each test for which there is sufficient volume of specimen available, giving you access to more information.
*Click the green and white plus sign beside each question to view the answer.
Can a hair test be manipulated by the donor?
Yes. Bleaching, perming, dyeing and straightening can affect the outcome of a hair test. Cosmetically treated hair should not be collected.
Can a hair test be used to prove that a previously taken urine test was inaccurate?
No. The results of any second collected specimen have absolutely no bearing on the validity of the results of the first collected specimen. Furthermore, each matrix has its own advantages, disadvantages and limits of interpretation.
Can I use the reported value (the number) from a hair, nail, meconium, umbilical cord tissue, or urine test to determine how much or how often someone is using a drug (either prescription of illicit)?
No. These specimen types act as reservoir, where drugs and their metabolites may accumulate and/or degrade over time. When testing any reservoir matrix, it is impractical to back-track to determine time, dosage, or frequency. There are too many variables involved. The reported values (the numbers) have no therapeutic or clinical value. You cannot use the number to estimate how much the donor used or to what extent the donor was exposed.
Can the reported quantitation of drug or metabolite in hair, nail, meconium, umbilical cord, or urine be used to determine the timing of the drug use, how often the donor uses the drug, or the extent of the donor’s drug use?
No, when testing a reservoir specimen type, a specimen type where analytes tend to accumulate, you may not backtrack to determine time, dosage, or frequency. The result is positive or negative for the appropriate detection window associated with the specimen type.
Does the sample need to be frozen?
No, the sample may be shipped ambient.
Have results been used in court cases?
Yes, the analysis of a number of tissue types for the presence of drugs of abuse has been used in every state for decades. Specifically, our umbilical cord testing has been used to provide evidence of drug use by the mother in numerous states. Additionally, the detection of drug in umbilical cord was used as evidence of maternal drug consumption in a murder case in South Carolina and that interpretation was upheld on appeal to the SC Supreme Court.
How do PEth results differ from Urine EtG/EtS results?
Recent studies have indicated that low-level positive EtG results can be produced by certain agents like hand sanitizers and mouth wash (incidental exposure). Research indicates that the volume of alcohol required to trigger a positive PEth result is far above the level available from incidental exposure.
How much is needed for an adequate urine sample?
Requested sample volume is 10 milliliters.
Why are both ethyl sulfate (EtS) and ethyl glucuronide (EtG) included in urine testing for alcohol use, but only EtG in fingernail or hair testing?
A: For urine testing, it is standard practice in the field of toxicology to include both EtS and EtG, because EtG is subject to bacterial production and degradation if a urine sample is contaminated (e.g. when the donor has a urinary tract infection). EtS is not subject to bacterial production or degradation, and provides a second, more reliable alcohol biomarker in these urine contamination scenarios. Other specimens types, such as fingernails and hair, do not have this issue, so only EtG is measured in those sample types.
What is the detection window for urine?
A sample of urine provides a drug history from the last two to three days for most drugs, and an even longer period for marijuana.
Will a UTI affect the result of drug and/or alcohol testing?
Certain bacteria may interfere with drug detection but will not generate a false positive. Fermenting bacteria in the presence of excess glucose may produce ethanol in the bladder and in the specimen cup.