Referred Tests
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Test ID: ETGX
Ethyl Glucuronide Confirmation, Chain of Custody, Random, Urine
Useful For 
Suggests clinical disorders or settings where the test may be helpful
Monitoring abstinence in clinical and justice system settings using ethyl blucuronide and ethyl sulfate as direct biomarkers or metabolites of ethanol
This chain-of-custody test is intended to be used in a setting where the test results can be used definitively to make a diagnosis.
Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
Adulterants testing will be performed on all chain-of-custody urine samples as per regulatory requirements.
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Ethyl glucuronide and ethyl sulfate are minor metabolites of ethanol that are detectable in body fluids following alcohol consumption and, less commonly, following extraneous exposure. Ethyl glucuronide (EtG) and ethyl sulfate (EtS) are direct biomarkers or metabolites of ethanol. EtG and EtS can be detected up to 5 days in urine using a cutoff of 500 ng/mL.(1)
Chain of custody is a record of the disposition of a specimen to document who collected it, who handled it, and who performed the analysis. When a specimen is submitted in this manner, analysis will be performed in such a way that it will withstand regular court scrutiny. Chain of custody is required whenever the results of testing could be used in a court of law. Its purpose is to protect the rights of the individual contributing the specimen by demonstrating that it was under the control of personnel involved with testing the specimen at all times; this control implies that the opportunity for specimen tampering would be limited.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
Negative
Cutoff concentrations:
Ethyl Glucuronide: 500 ng/mL
Interpretation Provides information to assist in interpretation of the test results
A positive interpretation will be given if either the ethyl glucuronide result is greater than or equal to 250 ng/mL and/or the ethyl sulfate is greater than or equal to 100 ng/mL.
A "high" positive (ie, >1,000 ng/mL) may indicate:
-Heavy drinking on the same day or previously (ie, previous day or 2).
-Light drinking the same day
A "low" positive (ie, 500-1,000 ng/mL) may indicate:
-Previous heavy drinking (ie, previous 1-3 days).
-Recent light drinking (ie, past 24 hours).
-Recent intense "extraneous" exposure (ie, within 24 hours or less).
A "very low" positive (ie, 100-500 ng/mL) may indicate:
-Previous heavy drinking (ie, 1-3 days)
-Previous light drinking (ie, 12-36 hours).
-Recent "extraneous" exposure.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Please note that incidental exposure to alcohol in many daily use products (ie, hand sanitizers, mouthwash) may result in detectable levels of ethyl glucuronide (EtG) and ethyl sulfate (EtS).
In addition, upper respiratory infections as well as beta glucuronidase hydrolysis may lower levels of EtG, but do not seem to affect EtS.(2)
EtG/EtS results should be interpreted in the context of all available clinical and behavioral information.
Clinical Reference Recommendations for in-depth reading of a clinical nature
1. Reisfield GM, Goldberger BA, Crews BO, et al: Ethyl glucuronide, ethyl sulfate, and ethanol in urine after sustained exposure to an ethanol-based hand sanitizer. J Anal Toxicol 2011;35:85-91
2. The role of biomarkers in the treatment of alcohol use disorders. 2012 Revision Substance Abuse and Mental Health Services Administration. Spring 2012;11(2):1-7