Frequently Asked QuestionsA selection of frequently asked questions relating to DNA, drug and alcohol testing
What does “not excluded as the biological father” mean?
What does “excluded” as the biological father mean?
What does the “probability of paternity” mean?
How is a DNA test done?
The DNA test compares fragments of highly variable DNA, called Short Tandem Repeats (STR).
Through a series of chemical reactions, DNA from the child and the alleged father is extracted. Using a technique called PCR (Polymerase Chain Reaction); 24 STR markers from different chromosomes of the child and alleged father 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 alleged father, it is possible to establish the shared STR markers between them.
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 tecnical data table lists each STR marker tested with the likleyhood of any matching DNA Paternity Index (PI).
What is the paternity index (PI)?
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. The higher the CPI the more likley the tested man is the father.
Who will receive the results?
What happens to the DNA after the test is carried out?
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 the name on a birth certificate, for immigration applications or appeals, or for child maintenance or custody disputes, you will need a legal DNA test. You can contact our Customer Services team on 01 402 9466 or email email@example.com for more information.
How accurate is hair strand analysis?
AlphaBiolabs uses an analytical technique called High Performance Liquid Chromatography tandem mass spectrometry (HPLC/MS/MS), which detects and quantifies drugs of abuse, enabling us to unambiguously differentiate between each individual drug we analyse for and their related compounds.
How can we assure the quality of the results?
AlphaBiolabs is accredited to the international quality standard ISO17025 and also certified to the ISO 9001 standard. In addition to our in-house quality control procedures, we also participate in external proficiency testing schemes (GTFCh and SoHT) that submit blind Quality Control samples to the laboratory and assesses the laboratory’s performance.
These quality measures ensure the analytical technique is complying fully with industry requirements, the application of best practice and the use of up-to-date methodology. The implementation of these standards provides assurance that the analyses are accurate and that AlphaBiolabs provides a high quality service.
Why should I choose a hair strand analysis?
Depending on the length of the sample donor’s hair, hair strand analysis can provide a historical record of drug misuse/abstinence for up to 12 months (longer on some occasions).
Segmented analyses or an overview?
If you only require a drug test to provide an average result over a longer period of time (e.g. 3 months), then an overview analysis will provide this.
How soon after use can a drug be detected in hair?
However, if you require a test to cover drug consumption during this most recent 2 weeks, we would recommend waiting at least 3 to 4 weeks before sample collection.
Can we detect the difference between prescription/over-the-counter drugs and illegal substances?
This means that each drug is unequivocally identified and cannot be confused with another drug (e.g. the use of lignocaine in dental treatment cannot give rise to a positive cocaine result etc.).
What happens if the sample donor has very little or no head hair?
Therefore deriving an accurate time frame associated with body hair samples is not possible. It can however be assumed that any drug use occurs within the total life cycle of the body hair, which can be up to 12 months. Furthermore, as body hair exhibits a larger amount of hair in the dormant phase than head hair, segmentation is not possible for body hair.
How does AlphaBiolabs establish its cut-off levels?
How much hair is needed for testing?
What about environmental exposure to a drug?
Although the possibility that this scenario will cause false positive results cannot be completely removed, safeguards are put in place to significantly reduce the possibility of this occurring. These include; the application of recommended cut-off levels, chemical washing of the hair three times prior to analysis (to remove/reduce any drug that may be present on the surface) and, in most cases, the detection of the drug itself and its metabolite (providing supporting evidence that a drug has been directly ingested by an individual).
Can chemical treatments on the hair affect the results?
The extent of the loss will depend on the cosmetic treatment used and the drug present. Therefore, sample donors who are occasional users of drugs may potentially give negative test results. However, more frequent drug users may still test positive but the levels of the detected drugs would be less than if the hair was untreated.
Can dread-locked hair be analysed?
What is chronic and excessive alcohol consumption?
What is a Liver Function Test?
Historically, an increase of Gamma GT (one of the enzymes monitored in an LFT) has been used to indicate chronic and excessive alcohol consumption.
Indeed, it has been reported that for a healthy individual, at least 60 grams of alcohol per day, for a minimum of four weeks is required before an elevation of GGT may be observed, but that only 30–50 percent of excessive drinkers in the general population will show an increased Gamma GT result.
It is strongly recommended therefore to use the LFT results in combination with results from other tests such as CDT in blood and ETG and FAEE in hair. An LFT test can only give a result representing approximately four weeks prior to sample collection.
Can medications affect LFT results?
However, it is not possible to determine who will be affected in this way when they start a medication. This is why a GP will often monitor an individual’s liver function (by performing LFT) following their introduction to a new medication in order to monitor and ensure that the consumption of the drug is not causing additional problems within the liver.
What is a CDT test?
Indeed, carbohydrates are not attached as they should be to transferrin (i.e. Carbohydrate Deficient Transferrin, or CDT are created). It is generally accepted that it takes the daily consumption of more than 60 grams of alcohol for a minimum of 1–2 weeks to increase CDT concentrations to an abnormal level.
It should be noted that an episodic binge drinking session is unlikely to cause an elevation of the CDT concentration in the blood.
A CDT test can only give a result representing approximately four weeks prior to sample collection.
Blood alcohol tests in pregnant and post-partum women
Furthermore, due to the changes in blood volumes and the circulatory system of a pregnant woman, it is advised that as a general principle CDT should not be measured. LFT and CDT testing should not be started again until they are at least 8 weeks post-partum.
Blood alcohol tests following blood transfusions
Indeed it is also advised to wait at least 2 months following a blood transfusion before starting LFT and CDT testing again.
What are FAEE and EtG hair alcohol tests?
These compounds are then distributed around the body and a small portion become incorporated in hair (via different routes). The hair can then be analysed for these compounds and compared against Society of Hair Testing (SoHT) recommended cut-off levels (for either a 3 cm or 6 cm long segment of hair from the root).
Levels of EtG and FAEE above the cut-off are consistent with the excessive and chronic consumption of alcohol during either the 3 or 6 month period of investigation.
Why should I get EtG and FAEE tests in combination?
This includes the possible removal of water soluble EtG through very regular washing and/or false positive FAEE findings due to the direct application of cosmetic products containing alcohol (such as hairspray, mousse, gel and wax).
It is issues such as these (and others) that led to the ruling of LB Richmond v B & W & B & CB (2010) EWHC 2903 (Fam), which recommends that:
- When used, hair tests should be used only as part of the evidential picture and the hair analysis findings should not be used in isolation but in conjunction with all evidence for the case including witness reports, other tests performed, and any clinical assessments carried out.
- Because of the respective strengths and weaknesses of EtG and FAEE tests, if hair tests are being undertaken, both tests should be used.