To view the Urine Testing Panels and Collection Instructions, click here.
Direct Alcohol Biomarkers – EtG and PEth Webinar
Direct Biomarkers of Alcohol Use by Dr. Adam Negrusz
Clients Receive Custom Solutions with USDTL 01-Jan-2010
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
*Click the green and white plus sign beside each question to view the answer.
Can a second test of a different specimen type be used to prove that a previously taken 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 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.
Can the use of any isopropanol (rubbing alcohol) containing product explain an ethyl glucuronide (EtG) result?
No, the use of any product that contains isopropanol will NOT explain the presence of EtG. Isopropanol forms its own glucuronide, isopropyl glucuronide and does not interfere with the LC-MS/MS detection of ethyl glucuronide (EtG).
Can I use the reported value (the number) from a hair, nail, meconium, umbilical cord, or urine test to determine how much or how often someone is using a drug (either prescription or illicit)?
No. These specimen types act as a 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.
Does the use of Xylocaine® (lidocaine) explain a positive cocaine or cocaine metabolite in any specimen type?
No, Lidocaine will NOT explain a GCMS or LCMSMS confirmed positive cocaine or cocaine metabolite in any specimen type (blood, urine, hair, nails, meconium, umbilical cord segment, etc…). The compounds are very structurally different and breakdown into very different metabolites.
Can the drug test result from a maternal specimen (such as maternal hair, nail or urine) differ from the result from a neonatal specimen such as neonatal urine, meconium or umbilical cord tissue segment?
Yes, the results can be different. Each specimen type has its own advantages, disadvantages, threshold to positivity, and detection time window. One test does not refute the other. The test results are cumulative. For instance, if the maternal urine is positive for cocaine and newborn meconium is positive for methamphetamine, the results do not rule each other out. The appropriate interpretation is that the mother consumed both cocaine and methamphetamine.
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.
If the quantity of drug or alcohol metabolite detected is high, could that be an indication that the donor (1) was consuming a large amount, (2) was using recently, or (3) was using frequently?
There are too many variables for anyone to know time of use, dosage, or frequency from the result(s) of a drug test. Reservoir matrices such as hair, fingernail, umbilical cord, and meconium continuously collect drug and alcohol biomarkers. This makes it difficult to determine specific details of use. Because the biomarker is collected over a period of time, the results represent total accumulation that cannot be pin-pointed to specific times/dates/dosages, etc.
May 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.
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.
Why was one matrix positive and another negative on the same donor?
There are several explanations for this.
- Different sample matrices have different detection time frames. The result of any second collected specimen has no bearing on the validity of a first collected specimen. For example, a hair sample with a three month window of detection might test positive for a particular substance, while a urine sample from the same donor, with a 2-3 day window of detection, might test negative. In this case, the donor has used that substance within the past three months, but may not have used it within the most recent three days.
- The result of any second collected specimen has no bearing on the validity of a first collected specimen. Therefore, a negative result observed for the umbilical cord does not refute a positive result observed on the maternal urine specimen and the reverse is true as well. There are many legitimate reasons for discrepant urine and umbilical cord results.
- The urine specimen was a screen only result and was not confirmed using an appropriate mass spectrometric method. The screen only urine result is a clinically valid result, however, without an appropriate mass spectrometric confirmation, the urine result has no value in a forensic proceeding.
- Lastly, some placentas can prevent some compounds from reaching the fetus. There are documented cases of maternal ingestion without in utero exposure.
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.