Frequently Asked Questions

Frequently Asked Questions

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

Are the PEth collection supplies CLIA-waived?

The collection supplies that we have are not CLIA-waived, as we are a CLIA accredited laboratory and must follow all accreditation standards.

Are you aware of any other labs splitting specimens for PEth or sending two specimen cards filled with dried blood for testing?

There are no other labs that do commercial dried blood spot PEth testing, so there are no labs for comparison.

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 a hair test determine how much or how often someone is using a drug?

No. Hair is a reservoir matrix, where drugs can collect and/or degrade over time. When testing any reservoir matrix, you are unable to back-track and determine time, dosage or frequency because there are simply too many variables involved.

Can a nail test be used to prove that a previously taken hair test was inaccurate?

No, the result of any second collected specimen has absolutely no bearing on the validity of the result of any first collected specimen because you have no idea what the donor did between time A and time B.

Can a single serving of ethanol alcohol (12 oz. beer, 5 oz. wine), cause a positive Phosphatidylethanol (PEth) using a 20 ng/mL cut-off in whole blood or dried blood spot?

The literature suggests that it requires multiple servings of ethanol on a single occasion to produce a positive PEth result. PEth has a half-life of approximately 4.5 days.

Can Meconium Testing for FAEE be run in conjunction with testing for panels for illegal drugs?

Yes, Meconium Testing 5-, 7-, 9- and 12-drug panels can all be bundled with Meconium Testing for FAEE.

Can someone test positive in fingernail because of passive or environmental exposure?

Yes, environmental exposure versus ingestion must be resolved when interpreting drug tests using fingernails.

Can someone test positive in hair because of passive or environmental exposure?

Yes, drugs are incorporated into hair by three major routes: environmental exposure, sweat and sebum from the scalp and blood flow through the follicle. Environmental exposure however will only generate a positive for the parent drug. Example: methamphetamine only. The other two mechanisms lay down drug and drug metabolites. Example: amphetamine/methamphetamine positive.

Can the use of isopropanol (rubbing alcohol) containing product explain a positive PEth result?

There are zero instances in the scientific literature (over 25,000 articles) of anything other than consumption of ethanol creating Peth results.

Can we order just the blood spot cards?

Yes, during your account setup process just inform us that you will only need the blood spot cards.

Can we purchase the collection supplies for training purposes?

We do not sell collection supplies. All account set-up paperwork must be completed before we ship the supplies to your facility.

Can we put blood spot cards into a sealed plastic bag?

Before placing blood spot cards into a sealed plastic bag, you MUST allow the card to dry for one full hour. Once dry, you can place dried blood spot cards in a plastic bag but you MUST include desiccant packs to reduce the moisture in the bag. It is highly recommended that the cards are placed in a non-plasticized envelope for transport when possible to avoid any issues with moisture.

Can we transfer blood from a tube to the dried blood spot card?

No, it is recommended that the dried blood spot card heel stick collection protocol from your organization is used to collect blood on a dried blood spot card. Whole blood can be submitted directly to the laboratory in a gray-topped anticoagulant blood tube.

Can we transfer whole blood specimen to the blood spot card?

Whole blood can be submitted for PEth testing by sending in the whole blood tube. We do not recommend transferring blood collected under a chain of custody via venipuncture to a dried blood spot card. 

Can you test for alcohol exposure in meconium?

Yes, alcohol exposure can be tested individually or by adding the Meconium FAEE add-on to any of the Meconium Testing drug panels. The FAEE add-on screens for Fatty Acid Ethyl Ester, a direct ethanol biomarker, including exposure to ethanol (drinking alcohol). To report out a positive FAEE result, the laboratory must verify that the specimen was collected less than 18 hrs from the time of birth. If the final time of collection is greater than 18 hours from the time of birth, the specimen will be rejected for FAEE testing, and the following comment will be added to the specimen report: "Not suitable for FAEE testing due to delayed specimen collection."

Can you test for alcohol exposure in umbilical cord?

Yes, alcohol exposure can be tested individually or by adding the Umbilical Cord Testing EtG add-on to any of the Umbilical Cord Testing drug panels. The EtG add-on screens for Ethyl Glucuronide, a direct alcohol biomarker, indicating exposure to ethanol (drinking alcohol).

Do doctors know about Meconium Testing for FAEE? Does USDTL have a means of informing doctors of this new test?

Yes and No. Many physicians know about the test from scientific publications and literature from USDTL. There are, however, many physicians that are not yet knowledgeable about the test and have never ordered it. If your local physicians do not have the necessary information to order the test, call Client Services at 1-800-235-2367 and the scientific information will be supplied.

Do you have any recommendations on how to ship specimens internationally?

We are not able to help with any of the shipping coordination or additional questions regarding international testing as we do not know the local laws.

Does race make a difference in hair testing results?

Hair color, not race, is one of the most important variables in determining the quantity of drug found in the hair. Dark hair binds drug tighter than light hair.

Does the sample need to be frozen?

No, the sample may be shipped ambient.

Does Umbilical Cord Testing use umbilical cord blood or umbilical cord tissue?

Umbilical Cord Testing uses 6 inches of umbilical cord tissue that has been drained and patted dry.

Have meconium results been used in court cases?

Yes. Meconium results, when determined using two separate, validated laboratory procedures based on different scientific principles, are forensically defensible. Our laboratory procedures have been scrutinized by laboratory inspectors, and our test results have been upheld in court.

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.

Have you ever had any challenges to positive PEth test results in whole blood and/or dried blood spot?

Extensive research has helped create a good understanding of PEth and how it can be utilized both in research and commercially. This has helped eliminate major challenges that other, less researched assays, might face.

How are meconium results reported to the hospital?

Generally, results are reported to a secure fax at the hospital facility. This number is confirmed as secure when your account is initiated. As encryption programs improve, developments in e-mail and web-based internet reporting are being developed. Under no circumstances are results ever given via telephone, since the laboratory has no definite indication of the identity of the caller.

How can DHS Methamphetamine specialists use information about Meconium Testing for FAEE to improve our protection of children?

Results from Meconium Testing for FAEE give DHS personnel direct information about newborns who have been exposed to high levels of Ethyl Alcohol. Approximately 3 percent of all newborns have been exposed to high levels of alcohol and these newborns’ meconium specimens have FAEE levels greater than 10,000 ng/gram. This “red flag” level represents only one quarter of the total number of alcohol exposed newborns. Three quarters of alcohol exposed newborns were exposed to small or moderate amounts of alcohol and represent lower risks of manifesting signs and symptoms of Fetal Alcohol Spectrum Disorder. The newborns with FAEE levels greater than 10,000 are at higher risk for Fetal Alcohol Spectrum Disorder, as well as a higher probability of living in a chaotic environment where abuse or neglect is more likely.

How do drugs get into nails?

Drugs are distributed via the blood supply to the nail cells and the nail bed. Nails grow not only in length but in thickness as well. As the nail grows in thickness, it creates layers of drug history.

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 does a PEth test result correlate with “dangerous” versus “social” drinking?

The testing can only detect whether PEth is present in the specimen, it cannot determine time, dose, or frequency of use. The literature suggests that it requires multiple servings of ethanol on a single occasion to produce a positive PEth result.

How does NIDA and the court system view the validity of Meconium Testing for FAEE?

NIDA (The National Institute on Drug Abuse) actually is NOT the institute that funded the original research for FAEE in meconium. It was the National Institute for Alcohol Abuse and Alcoholism (NIAAA) that provided USDTL with the grant funds to develop Meconium Testing for FAEE. This test has become the de facto standard for laboratory diagnosis of fetal alcohol exposure and is in routine use all over the United States and Canada. Courts have held that Meconium Testing for FAEE meets both the Fry and Daubert standards, and the results are admissible in adversarial proceedings.

How does using a forensic drug test help the child later in life?

There are several reasons detecting a substance exposed newborn is important. Early detection provides many more options than detection at a later stage in the child’s life, and 

  1. Early detection of fetal alcohol syndrome (FAS) and fetal alcohol effect (FAE) allow newborns to be identified and enrolled into early intervention and community programs. New programs are showing dramatic improvements in children identified earlier in life. 
  2. Detection of a exposed child can allow help, intervention and treatment to be offered to the mother, so that exposure during future pregnancies may be prevented. 
  3. As programs, understanding, and treatments improve, substance exposure detection, at a very early stage, can only help the outcome of the child, mother and family.

How long can drugs be detected in body hair?

Body hair has a different growth cycle compared to head hair. Body hair may go dormant and remain in place up to one year. A positive result reflects exposure up to 12 months.

How long can drugs be detected in head hair?

Once a drug is incorporated into hair, it begins to slowly leach out due to normal daily hygiene and exposure to the elements. Most drugs have disappeared by three months. Furthermore, the laboratory only analyzes the first 1.5 inches (3.9 centimeters) nearest the scalp. Hair grows at an average rate of 0.5 inches per month.

How long does the laboratory keep remaining umbilical cord tissue?

Negatives are kept for 1 week, and positives are kept for 1 year.

How many days until I receive results?

Screen negative results will be transmitted to your secure fax on the same day on which the laboratory receives the sample. Screen positive results will be confirmed using a separate technique and reported 2-3 business days after specimen receipt.

How much blood is required for a PEth testing specimen?

5 individual large drops on a dried blood spot collection card or 5 milliliters of whole blood collected in a gray-top collection tube containing anticoagulant.

How much breast milk is needed?

Requested sample volume is 10 milliliters collected in a sterile container.

How much fingernail needs to be collected?

The optimum amount of nail clippings needed is 100 milligrams. If trimming all 10 fingernails, each clipping must be at least 2 millimeters to 3 millimeters long.

How much is needed for an adequate urine sample?

Requested sample volume is 10 milliliters.

How much meconium is needed for the test?

A minimum of 2 grams of meconium (a teaspoon) is normally required, although some tests, such as "confirmatory tests only" can be performed with less. However, for best results, we recommend collection of the entire passage of meconium until the milk stool appears.

How should staff proceed with sending a specimen for testing on premature neonates that often do not stool for 3-5 days?

While these meconium specimens are fine for the routine drugs of abuse, these specimens (due to the delayed passage) should not be tested for FAEE.

How should umbilical cord tissue be stored?

The sample is stable at room temperature for 7 days, can be refrigerated (2-8° C) for up to 3 weeks and frozen (< -10° C) up to 1 year.

Is testing PEth in dried blood spot and whole blood the same price?

Yes, the price is the same whether it is whole blood or dried blood spot.

Is there a proportion of consumption related to each increasing result? i.e. is 100 ng/mL 5 times more consumed than a 20 ng/mL result?

Testing can only detect whether PEth is present in the specimen, it cannot determine time, dose, or frequency of use. PEth has a half-life of 4.5 days so the results are contingent on when the donor last drank and how much they have been drinking.

Is there a specific shipping company we would need to use or is that at our discretion?

You may use any shipping courier of your choice.

Is there a timeframe in which collected PEth specimens can no longer be tested for research purposes?

With strictly research specimens, our laboratory has more flexibility regarding testing timeframes. In general, specimens should not be tested beyond their stated timeframe for stability. The Sponsor should note that any results from testing specimens beyond their stated timeframe for stability can be less reliable.

Is umbilical cord genetically fetal tissue or tissue of the mother?

The fetus generates umbilical cord during the first five weeks, therefore, it is fetal tissue.

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.

Mother tested negative for chemicals on a saliva test, 8 days later, her baby was born and its meconium drug screen showed the presence of methamphetamine and amphetamine. What does this mean?

This is an excellent example of the difference in the time window between meconium and saliva. Saliva will reflect use for up to 48 hours after use of methamphetamine. Meconium reflects weeks of past exposure history. In this case the maternal use did not fall into the time window available from a saliva sample but the meconium specimen did provide a broad enough window to identify the newborn as methamphetamine-exposed. The take home message is that meconium reflects weeks to months of exposure history whereas urine and saliva provide hours to days of history.

Please describe the new meconium test for alcohol.

Meconium Testing for FAEE is a test of the non-oxidative metabolites of ethanol called Fatty Acid Ethyl Esters. These metabolites are the chemical combination for endogenous fatty acids present in the blood of a fetus and Ethyl Alcohol. These new compounds, which only form when the fetus is exposed to Ethyl Alcohol, are deposited into the fetus’s meconium and can then be detected and quantified from the newborn’s meconium after delivery. The amount of the Fatty Acid Ethyl Esters found in the meconium is representative of the amount of Ethyl Alcohol the fetus was exposed to during the last half of the pregnancy.

Q: 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.

Should I keep the collected dried blood spot specimens in a cooler or just at room temperature?

Please keep specimens at the normal air-conditioned lab temp ±26 degrees Celsius or in the fridge.

The umbilical cord was fixed in formalin. May it still be used for the Umbilical Cord Testing?

No, Umbilical Cord Testing has not been validated for tissues that have been fixed in formalin.

We are testing a neonate for FAEE and a drug panel; how should we proceed with testing the meconium with the new change in policy?

The ideal collection of meconium is collecting all of it from beginning until it has been excreted. If you are testing the specimen for FAEE, it must be collected within the 18-hour time frame. There is always the option of testing the cord tissue for EtG as a backup.

What are the meconium sample storage requirements?

Drugs and metabolites are stable in meconium for up to 2 weeks at room temperature. However, refrigerated or freezer storage is preferred. Alcohol metabolites, specifically FAEE, are sensitive to heat and light and therefore the PREFERRED shipping method is frozen on dry ice. Since this method is both difficult and expensive, most institutions send at room temperature and realize that the FAEE concentrations may be reduced. USDTL accepts specimens that are shipped at room temperature.

What does a positive hair test result mean?

The only interpretation that can come from a positive hair test is that the individual used or was exposed to drug during the three months prior to collection.

What does a positive newborn PEth result mean? What does the quantitation or number mean?

A positive result means that Phosphatidylethanol (PEth) was detected in the specimen. Due to ethical issues, time-dose studies cannot be performed to determine more specific answers to these questions.

What does a positive PEth mean? Does it measure only heavy/binge drinking or will it be positive after consuming a drink per day over a few days?

A positive PEth result means that the donor has consumed ethanol sometime during the last 2-4 weeks (approximately).

What does USDTL provide in the PEth dried blood spot collection supplies?

  • 2 blood spot lancets
  • 2 tamper-evident seal
  • 2 non-ethanol based alcochol pads
  • 1 blood spot card
  • 1 blood spot drying box

What information can you give on testing of meconium and why some experts state that it depends what part of the meconium is sent into labs as to what will test positive?

The single most important element of collecting meconium for drug and alcohol testing is obtaining the entire quantity of meconium that the newborn passes, being careful that it is not to mix in the milk stool. This is extremely important in order to obtain the maximum time window of exposure for the infant. Meconium is a HETEROGENOUS material and each portion passed reflects a different time of gestation. This is due to the extreme viscosity of the meconium mass and the lack of significant mixing in the fetal intestine. If only a portion of the total meconium is collected and sent for analysis, it may reflect a period of abstinence, and an exposed newborn may go undetected.

What is Child Hair Testing, and how is it different from regular hair drug tests?

Child Hair and Nail Testing are a modified hair and nail drug tests designed to increase environmental exposure detection in children. The assays are often used by social service agencies involved in custody cases.

What is FAEE referred to in memo re: meconium collection?

Fatty Acid Ethyl Esters - a long term ethanol biomarker.

What is m-OH-BZE?

Meta-hydroxybenzoylecgonine (m-OH-BZE) is a metabolite of cocaine which is often present in the meconium of neonates born to cocaine-using mothers. It is a minor metabolite in adults, but it has been identified as the only cocaine metabolite present in 23 percent of meconium samples screening positively for cocaine. If a laboratory does not include m-OH-BZE in its confirmation profile, there is a risk of not identifying up to 23 percent of cocaine exposed newborns.

Lewis D, Moore C, Becker J, Leikin J. Prevalence of meta-hydroxybenzoylecgonine (m-OH-BZE) in meconium samples. Bulletin of the lnt.Ass.Forens Toxicol 1995;25(3):33-36

What is provided in the newborn PEth collection supplies?

PEth collection supplies include 2 lancets, 2 non-ethanol prep pads, gauze, a dried blood spot collection card, and a dried blood spot drying box.

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.

What is the length of time PEth dried blood spot specimens can be stored while still maintaining their integrity?

  • Room Temp = 1 year
  • Refrigerated = 1 year
  • Frozen = 1 year at 20&deg;C (-4&deg;F)

What is the length of time that PEth specimens can be stored while still maintaining their integrity?

  • Room Temp = 1 year
  • Refrigerated = 1 year
  • Frozen = 1 year at 20ºC (-4ºF)

What is the length of time that specimens can be stored while still maintaining their integrity?

Dried blood spot cards can be stored up to 1 year at room temperature, refrigerated, or frozen. Whole blood tubes can be stored for 1 week at room temperature, 1 week refrigerated, or up to 1 year frozen (can be thawed up to 3 times).

What is the longest time PEth will remain positive after problem drinking stops?

The Peth test is designed to detect heavy drinking up to approximately 2-4 weeks prior to collection. This is because PEth has an average half-life is 4.5 days. This means that every 4.5 days the level of Peth is cut in half. For example: If an average person with a PEth level of 1000 ng/mL stops drinking, it would take approximately 2.5 weeks for them to fall below the 20 ng/mL cut-off level.

What is the minimum shipment requirement for PEth specimens for research purposes?

Please send at least 10 or more specimens per batch; preferably overnight with tracking capability. You can use any courier of your choice. Please have specimens arrive at USDTL between Monday and Friday.

What is the newborn blood specimen requirement for PEth testing?

We require that all 5 spots on the dried blood spot card be filled completely for submission to testing. If sending in whole blood, we require 2 mL collected in a gray-topped anticoagulant blood tube.

What is the preferred method of sanitation prior to specimen collection?

Follow your local protocols for collection of dried blood spot or whole blood. DO NOT use any ethanol based products.

What is the relationship between alcohol consumed and FAEE levels?

Based on two research studies reported in peer-reviewed literature, the total FAEE levels in excess of 10,000 ng/g show significant ethanol exposure in the newborn. (Moore C, Jones J, Lewis D, Buchi K. Prevalence of fatty acid ethyl esters in meconium specimens. Clin Chem 2003;49(1):133-136)

What is the turnaround time for newborn PEth testing?

Turnaround time is 48 hours for screen negative with an additional 24-48 hours for specimens that require confirmatory testing. Turnaround time begins from receipt of the specimen into our laboratory.

What is the window of detection for meconium?

Meconium begins to form in weeks 16 through 20 of gestation. Therefore, depending on the gestational age of the newborn, a complete collection of meconium will represent approximately 20 weeks of maternal drug use history.

What is the window of detection for PEth?

Up to approximately 2-4 weeks depending on the starting concentration of PEth. 

What is the window of drug exposure for umbilical cord?

Dose/response studies have not been performed and will most likely never be performed for ethical reasons. However, when compared to meconium, which has a detection window of up to 20 weeks, Umbilical Cord Testing has demonstrated an agreement greater than 90 percent.

What type of alcohol wipes should I use?

ONLY use isopropyl alcohol wipes. DO NOT use any wipes or sanitizers that contain ethyl alcohol.

When will I receive breast milk results?

Results will be provided in two to three days after the sample is received in the laboratory.

When will I receive umbilical cord results?

Test  Negative Result Positive Result
Umbilical Cord Drug Panel 1 working day 2 working days
Umbilical Cord EtOH 2 working days 3 working days

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 do we test for EtG in hair and not FAEE?

FAEE is less sensitive and can produce false positives. Hairspray and other hair products can produce FAEEs in hair. There is no enzyme in our hair that can create ETG from those products.

Why is the PEth blood positive and the EtG negative in umbilical cord tissue?

There is no answer for this question as the results of any collected specimen have absolutely no bearing on the validity of the results of another collected specimen. Each matrix has its own advantages, disadvantages, and limits of interpretation. 

Why is Umbilical Cord Testing becoming the gold standard in newborn testing over meconium?

USDTL’s Umbilical Cord Testing is groundbreaking in newborn testing because it solves several problems:

  • Every newborn has an umbilical cord; meconium is not available for every birth.
  • Umbilical cord collection is a one-step procedure; meconium collection requires cumulative collections.
  • Umbilical Cord Testing offers improved positivity rates for Methamphetamine, Benzodiazepines and Opiates.
  • Umbilical Cord Testing improves the integrity of the chain-of-custody: only one donor and one collector are present during the collection. Meconium has multiple collections and multiple collectors.
  • Umbilical Cord Testing improves turnaround time because umbilical cord is ready for transport a few minutes after the birth, while meconium passages can be delayed for days before being sent to the lab.

Why test for fetal alcohol exposure when there is no treatment available?

There are several reasons why diagnosis of alcohol exposure is important. As with any disease, early diagnosis provides for many more options and treatments than detection at an advanced stage.

  1. Early diagnosis of fetal alcohol syndrome (FAS) and fetal alcohol effect (FAE) allow newborns to be identified and enrolled into early intervention and treatment programs. New programs are showing dramatic improvements in children identified earlier in life.
  2. Detection of an alcohol affected child can allow help, intervention and treatment to be offered to the mother, so that future FAS and FAE children may be prevented.
  3. When cocaine- and opiate-exposed newborns were first detected, there was no treatment. As programs, understanding and treatments improve, diagnosis at a very early stage can only help the outcome of the child, mother and family.

Why was the mother’s urine positive and the umbilical cord negative?

There are several explanations for this. Different specimen types have varying thresholds for positivity. For example, a single dose of methamphetamine 12 hours prior to collection is highly likely to produce a positive urine result, however less likely to generate a positive result for a specimen type with a longer detection window such as umbilical cord, meconium or hair.

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.

Will one-time drug use be detected in Fingernail Testing? How many times would they have to use drugs for it to be detected in nails?

Single doses do not guarantee a positive result. The number of doses required to generate a positive result is highly variable between donors.

With 5 dried blood spots, are all 5 spots used for testing PEth?

We typically use 2-3 of the blood spots for testing (assuming all five circles are filled). Ideally, there will be 1-2 blood spots left over and stored in the event a retest is requested.

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