Dr. Robert Bennett  -  Charleston DNA
M E D I C AL  -  L E G A L  -  F O R E N S I C
DNA - Drug - Alcohol - Paternity - Forensic Testing           RobertBennettPhD@gmail.com - (843) 571 - 7488  - 4 Carriage Ln #404 Charleston, SC          


Alcohol Toxicology Services
Dr. Bennett is able to provide the following services related to alcohol:
  • Provide expert testimony regarding all aspects of alcohol in the body, including the following:
  • Elimination of alcohol.
  • Absorption of alcohol in the body.
  • Retrograde Extrapolation of times and percentages of alcohol amounts.
  • Amount of alcohol needed to reach a given percentage for both men and women.
  • Determine the blood alcohol levels at times before the drawing of the blood, such as the time of death or time of an accident.
  • Amount of drinks to reach a recorded BAC.
  • Amount of alcohol eliminated for a given time.
  • Provide opinion testimony regarding the level of intoxication of a subject.
  • Provide expert testimony regarding all aspects of breath testing and the Breathalyzer.
  • Provide expert testimony regarding all applications of Regulations regarding alcohol in persons involved in driving while intoxicated.
  • Provide testimony regarding other breath testing instruments.
  • Provide expert testimony regarding applications of the law regarding testing of alcohol.
  • Review all documents from the police department's investigation of investigations of persons drinking alcohol.
  • Review all medical documents of testing of persons for alcohol use.
  • Review traffic accident reports, Alcoholic Influence reports, Accuracy Inspection reports, statements, depositions, interrogatories, and all documents regarding alcohol that pertains to the case.
  • Review testing results of other laboratories either by blood, breath or urine.


• Habitual Drunkenness • Public Intoxication • DUI •
• Open Container • Minors • Alcoholism •

Blood Alcohol

A Blood Alcohol Concentration (BAC) measures the amount of alcohol in a person's system at that moment. Used mostly to determine if someone is currently intoxicated or under the influence of alcohol. The same is true for a Breathalyzer of saliva alcohol test. Good for a few hours.


Urine Alcohol

A Urine Alcohol (EtOH) measures the amount of alcohol excreted from a person's system. It determines if the person has consumed alcohol recently (up to about a day). It does not determine if someone is currently intoxicated or under the influence of alcohol, just recent consumption.


Ethyl Glucuronide (EtG)

Ethyl Glucuronide (EtG) is a specific metabolite of ethanol and can only be found when alcohol has been recently consumed. EtG can be detected in urine for three to four days after alcohol consumption, thus indicating alcohol consumption during that time period. It does not determine if someone is currently intoxicated or under the influence of alcohol. This test is most widely used to determine if someone has consumed any alcohol, for example, over the weekend. EtG can be measured in hair and thus go back many months.


Carbohydrate Deficient Transferrin (dCDT)

The Carbohydrate Deficient Transferrin (CDT)/Gamma Glutamyl Transferase (GGT) test determines if someone has been engaging in HEAVY or unhealthy alcohol use (e.g. abuse). A POSITIVE CDT/GGT test result indicates that a person has consumed multiple alcoholic beverages on an almost daily basis for the past several weeks or longer.

Phosphatidyl Ethanol (PEth)

Phosphatidyl Ethanol (PEth)  is for detection of substantial alcohol use and is useful in CDT non-responders. PEth can also detect moderate alcohol use that is considered "risky" drinking. PEth can detect episodes on binge drinking (e.g. getting drunk one or more times). This test covers a time period of approximately 2-3 weeks.

The following table will highlight the different forensic alcohol tests that are available through my office for determining the extent and degree of alcohol use.

Blood AlcoholB.A.C.A few hoursAny alcohol useBlood
Urine AlcoholUrine EtOHUp to 1/2 dayAny alcohol useUrine
Urine Alcohol MetaboliteUrine EtG1-3 daysAny alcohol useUrine
Hair Alcohol MetaboliteHair EtGMonthsModerate alcohol useHair
Substantial AlcoholPEth2-3 weeksModerate  to heavy alcohol useBlood
Heavy AlcoholCDT/GGT3-4 weeks
Heavy alcohol use

These tests are typically not available forensically from a private Dr.'s office or a hospital lab. Hospital labs are prohibited by internal policy from preferring any outside tests for legal purposes. Our tests are available 7 days a week at any  location (home, office, court, jail). My personal cell phone number is (843)-571-7488. Affiliate offices are available statewide.



Carbohydrate Deficient Transferrin (CDT) testing is cleared by the Food and Drug Administration (FDA) as a biological marker for heavy alcohol consumption. Heavy alcohol consumption for most people is the consumption of multiple drinks on a regular (e.g. daily) basis. Heavy alcohol consumption for a period of one week or longer can elevate CDT protein levels above normal.

Elevated CDT is an indication that excessive drinking is disrupting the normal chemistry of the liver. It also means that excessive drinking may be affecting other body organs, especially the brain, and thus may be harmful to the person's medical or social / family functioning.

Cases of alleged habitual drunkenness can be objectively substantiated with the use of this test. However, as with many laboratory tests, not everyone is a responder. A significant number of heavy drinkers may pass this test. Therefore, as with any forensic evaluation, the absence of evidence (a Negative test result) does not prove to condition does not exist. Contrarily, a Positive test indicates (with a 95% specificity) that heavy alcohol consumption on a regular basis does exist.

The CDT protein level typically gradually returns to normal over 2 to 4 weeks following cessation of alcohol consumption, depending on the level of elevation. The CDT test is extremely sensitive to alcohol relapse and is an excellent tool to determine even minor relapses. Since CDT can remain elevated for two to four weeks, monitoring for relapse would not be needed more often than once approximately every four weeks.

CDT testing combined with GGT testing is very specific (>95%) for heavy alcohol use. CDT is the most reliable forensic alcohol abuse test to date. The CDT test yields useful objective forensic information for detection of chronic heavy alcohol use to aid in the identification of alcohol related diseases, including cognitive deficits and changes in mental functioning, as well as monitoring during treatment for alcohol abuse. CDT testing has been well documented in the peer reviewed medical literature as a marker for chronic alcohol consumption. It is extensively used in D.U.I. cases.

Typically, heavy alcohol consumption of a chronic nature (weeks to months) can also elevate GGT liver enzyme. GGT is a liver enzyme that responds to excessive, chronic metabolic burden placed upon the liver. Elevated GGT can be associated with persons who are alcohol dependent. GGT is used conjunctively with the CDT test, as it is the first liver enzyme that frequently is elevated in persons engaged in heavy alcohol use excessively and/or chronically.

CDT testing has been used by our office for court cases, mainly Family Court, for years and is widely accepted as a valuable forensic laboratory test. Currently, our office is the only forensic provider of this test. In addition to performing the test, clients are also offered a consultation as to how the test works, interviewed to ascertain their current level of alcohol consumption, pattern, and type, and the quantitative results of the test are correlated with the reported alcohol consumption profile. The comprehensive work up typically also includes an interpretation of the findings as to the health and wellness consequences of the level of alcohol consumption the test indicates.

The CDT test is an objective forensic tool to determine if the level of alcohol consumption is at an unhealthy level (physically and mentally) specifically for the person being tested. The cost of the test is $180 and includes the CDT test, the GGT liver enzyme test, and the comprehensive work up. The blood specimen is collected in a Serum Separator Tube (SST), spun (centrifuged), and tested in our Charleston, SC lab. Results are typically available in one to three days.