Can dread-locked hair be analysed?
Yes, but the time period will be approximate due to the process of dressing or preparing the hair.
Can someone become positive due to passive smoking/external exposure?
Reduce the likelihood by detecting the metabolites, washing the sample prior to analysis and applying cut-off levels.
How can we assure the quality of the results?
We are UKAS accredited to ISO17025, and quality controls are run with each batch of samples analysed.
What are the effects of bleach and hair dyes?
Excessive chemical treatment of the hair may leach out drugs.
Can body hair be used if no head hair is available?
Yes, body hair has a different growth cycle, time period more approximate. We do not test body hair for alcohol abuse.
What cut-off values are used?
International Society of Hair Testing (SoHT) cut-off values are used to prevent false negative/ positive results.
Could a positive result be due to contamination?
Hair analysis can distinguish between active use and contamination: hair samples are washed before testing, and can be analysed for parent drugs and metabolites; ‘cut-offs’ are used.
Why request segmented analysis?
Consecutive hair sections provide a historical picture of any drug use, exposure or abstinence.
What is FAEE & EtG hair alcohol testing?
There are two different types of hair alcohol testing. These are Fatty Acid Ethyl Esters (FAEE) testing and Ethyl Glucoronide (EtG) testing. FAEE and EtG are metabolites of alcohol that are created in the Liver. Elevated levels of FAEE and EtG in the blood or hair will strongly suggest chronic and excessive alcohol abuse. Combined with elevated CDT levels and a LFT it is possible to determine if alcohol is being abused by the sample donor.
What is a Carbohydrate Deficient Transferrin (CDT) Test?
Testing Carbohydrate-deficient transferrin (CDT) in blood is an effective way to determine if the sample donor is abusing alcohol. When elevated, CDT can be indicative of chronic, excessive consumption of alcohol, defined as at least 60 grams of alcohol per day on a routine basis for a minimum of two or three weeks.
What is a Liver Function Test?
A Liver Function Test (LFT) is a blood based test that will determine how efficient the sample donor’s liver is operating. The results will give a strong indication if the sample donors liver has been damaged. Combined with the results from other tests such as a CDT, EtG or FAEE, it can be determined if it is highly likely for the liver to have been damaged as a result of alcohol abuse.
Can we detect the difference between prescription/over-the counter drugs and illegal substances?
Yes, each drug has its own unique chemical structure and therefore has a different molecular ‘signature’. Because of this, when various drug molecules travel through the LCMS they behave differently. This difference can then be measured and analysed.
How does DNA Diagnostics establish its cut-off levels?
DNA Diagnostics uses the Society of Hair Testing (SoHT) guidelines whose cut-off levels are accepted industry-wide.
What happens if the sample donor has very little or no head hair?
Hair from other parts of the body can be tested such as underarm, beard, chest and pubic hair for drugs. However, body hair growth rates are slower than head hair and cannot be used to determine a time frame of drug use. We do not test body hair for alcohol abuse.
How much hair is needed for testing?
Approximately 50 – 60 strands are required for testing which appears to be the width of a thin pencil. If the head hair is collected from the most appropriate place, it should make no cosmetic difference.
Can chemical treatments on hair affect the results?
Hair can be damaged when chemical treatments such as bleach and hair dye are applied. If used extensively, it may be possible that the amount of drugs present in hair may be reduced. Therefore, sample donors who are occasional users of drugs may potentially test as negative. However, more frequent drug users may still test positive but the levels or detected drugs may be less than that detected in untreated hair.
When should I choose a hair strand analysis instead of urine or blood?
Hair strand analysis is essential when you need to monitor a person with a suspected drug or alcohol abuse history over an extended period of time. Hair strand analysis can provide a historical record of drug abuse / abstinence for up to 12 months or longer if required. Hair strand analysis is up to 10 times more sensitive than urinalysis.
How soon after use can a drug be detected in hair?
It takes approximately 5 – 7 days from the time the drug is ingested for the affected hair to grow above the scalp. If you require a test to cover for the first 7 days, we would recommend an observed urine analysis every 3 days.
What about environmental exposure prior to sample collection?
As an additional safeguard for sample donors, DNA Diagnostics washes all hair samples prior to performing any form of analysis to eliminate any effects that may be created by sample donors spending time with other people who may be smoking or taking illicit drugs. Our LCMS testing will also detect metabolites specific to various types of illicit drugs. These metabolites will only be present if the relevant drug in question had been ingested.
How accurate is a hair strand analysis?
DNA Diagnostics will screen the relevant sample and if drugs of abuse is detected the sample will enter a second stage of testing known as confirmation. For confirmation, we employ the latest legally defensible ‘platinum’ standard techniques known as HPLC/MS/MS (High Performance Liquid Chromatography coupled with Mass Spectrometry detection). By combining screening with confirmatory testing we will provide the most accurate form of testing available.
What happens if I want to take my results to court?
If you need the results of the test for court or for other legal purposes, such as changing a birth certificate, then you will require our Legal Test Service. Contact one of our friendly Customer Service advisors or visit our website for details.
What happens to the DNA after the test is carried out?
The extracted DNA is destroyed by incineration three months after the report has been sent out.
Who will receive the results?
The test report(s) will be given to the person(s) nominated on the DNA Profiling Consent Form, for whom everyone tested has given consent, and other authorised persons, where appropriate.
What is the combined paternity index (CPI)?
This ratio indicates how many times more likely it is that the results of the DNA analysis would have been obtained given that the tested man (alleged father) is the true biological father of the child submitted rather than an unrelated man picked at random from the same ethnic population. The CPI is based solely on genetic evidence and is determined by multiplying the individual PIs for each marker tested.
What is the paternity index (PI)?
The paternity index compares the likelihood that an allele was passed on by the alleged father to the child, to the probability that a randomly selected unrelated man of similar ethnic background has passed that same allele on to the child.
How is the test done?
The test compares fragments of highly variable DNA, called Short Tandem Repeats (STR). Through a series of chemical reactions, DNA from each individual is extracted.
Using a technique called PCR (Polymerase Chain Reaction), 24 STR markers from the different chromosomes of the individuals tested are copied. The products of the PCR are separated and measured to obtain a DNA profile. One-half of each person’s DNA information comes from their mother and the other half from their biological father.
By comparing the DNA profiles of the child with the mother, it is possible to establish the shared STR markers between them. The child’s STR markers not found in the mother’s profile must therefore come from the biological father. If the alleged father’s profile shares common STR markers with that of the child, then he is not excluded and may indeed be the true biological father.
A statistical analysis is then carried out to calculate the probability of paternity. An alleged father is excluded as the biological father if STR markers found in his profile are not shared with the child. The Test Results Table lists each STR marker tested with the probability of its occurrence in the general population.
What does the “probability of paternity” mean?
This is the percentage likelihood that a man with the genetic markers (alleles) of the alleged father is the true biological father of the child as compared to an untested and unrelated man of the same ethnic origin.
What does “excluded” as the biological father mean?
It means that the tested man (alleged father) does not have the expected profile required to be the biological father. He is therefore highly unlikely to be the true biological father.
What does “not excluded as the biological father” mean?
It means that the tested man (alleged father) has the DNA profile expected of the biological father. Therefore, the DNA test result confirms that the tested man (alleged father) is the true biological father of the child.