PEth Resources

PEth Resources

To view the PEth Testing Panels and Collection Instructions, click here.

PEth Videos

CCDG Presentation

Direct Alcohol Biomarkers - EtG and PEth Webinar

Direct Biomarkers of Alcohol Use by Dr. Adam Negrusz

Wisconsin Counties Use Long-Term Alcohol Biomarker Testing

Long-term Biomarkers for monitoring DUI/OWI offenders

Blood Spot Collection Training Video

Why Test For PEth in Blood

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PEth Infographics

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USDTL PEth Test In the News

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PEth Articles

A Moment In Time 02-Feb-2015

Made In The Blood 02-Feb-2015

The Long Game 02-Feb-2015

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USDTL PEth Research

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PEth Poster Presentations

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USDTL Assisted PEth Research

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PEth White Papers

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PEth Announcements

Report Change Notification Report Change Notification


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) Explained Quantity Not Sufficient (QNS) Explained


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.

Updated Policy Regarding Insufficient Specimen Volumes Updated Collection Instructions Updated Policy Regarding Insufficient Specimen Volumes Updated Collection Instructions


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.

Laboratory Awarded NIAAA Funding to Investigate The Epigenetics of Prenatal Alcohol Exposure Laboratory Awarded NIAAA Funding to Investigate The Epigenetics of Prenatal Alcohol Exposure


USDTL researchers will investigate the relationship between in utero alcohol exposure and epigenetics using Small Business Innovation Research funding from the National Institute on Alcohol Abuse and Alcoholism.

Laboratory First to Obtain Specimens from the Virtual Repository of Dried Blood Spots Laboratory First to Obtain Specimens from the Virtual Repository of Dried Blood Spots


USDTL is the first laboratory to be awarded specimens from the Virtual Repository of Dried Blood Spots, a new national database of dried blood spot specimens available for use in research.

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*Click the green and white plus sign beside each question to view the answer.

Can we use any tube for whole blood collection?

Please use only purple, gray, and green top tubes.

Do we need to spin (centrifuge) whole blood samples?


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. The PEth blood assay is an ideal tool to define low-level positive EtG results. The volume of alcohol required to trigger a positive PEth result is far above the level available from incidental exposure.

How much blood is required for a PEth testing sample?

5 individual large drops on a collection card.

How much blood is required for whole blood testing?

Requested sample volume is 5 milliliters.

What is the window of detection for PEth?

PEth is a mid- to long-term biomarker measurable after consumption of approximately 200 grams of alcohol. An individual consuming 1 drink per day for 6-7 days will produce a positive result. PEth can be measured for 2-3 weeks following the most recent alcohol consumption.

What is the window of detection for whole blood testing?

Whole blood testing for substances of abuse identifies usage over a 2-3 day period.

When will I receive whole blood testing results?

Results are available four to seven days after the sample is received in the laboratory.

Which phosphatidylethanol species do you measure during PEth testing?

Our PEth testing in dried blood spots measures the 16:0/18:1 PEth species.

Why was one matrix positive and another negative on the same donor?

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.

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For your convenience, USDTL provides test collection supplies at no additional charge.

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