Information about Non-Standard Samples for DNA Testing

DNA Extraction Success Rates

Non standard samples do not always guarantee that a DNA Profile will be obtained. Whilst for buccal swabs it is possible not to obtain DNA, such as in cases where the swabbing was not adequately performed or else the swabs grows mould due to damp storage conditions, in general problems with this type of sample are normally less than 2%. Therefore depending on the nature of the sample, there is usually associated a High, Medium or Low probability of success in extracting DNA from each type of sample.

High : Samples such as fresh blood stains or hairs with root where, for a qualified DNA laboratory, extracting DNA is relatively straightforward

Samples such toothbrush or cigarette butts where the success rate is influenced by a number of variables (e.g. heavy use vs light use, storage conditions etc).

Low : Sample such as teeth or bone where extracting DNA is relatively difficult and time consuming, and handled mainly by a highly specialised laboratory.

However, the above is usually only provided as a guideline, since it is not just the type of sample that is important but also other variables such as :

1. Poor storage conditions (e.g. damp environment, extreme heat or cold etc)
2. Poor sample handling (possible contamination with other DNA or dirt)
3. Not enough DNA present (e.g. heavily used toothbrush vs used once only)

It is also important to note that the success rate will also depend heavily on the ability of the laboratory performing the test. Not all laboratories that can perform DNA Paternity testing on normal swabs are able to successfully obtain DNA from a wide variety of other media. The more difficult the media (e.g. teeth and bone), the greater the specialisation and experience required.

Hair Paternity testing

Hair paternity testing is viable so as long as the hair has the follicle attached. This means that any hair you might have found lying around in the showers, or remains of cut or trimmed hair will not be any good for a paternity test. Nuclear DNA is not found in the hair shaft but only in the hair root or follicle. Hence, and naturally shed hair or cut hairs will not likely have any root attached. If you happen to have hairs, the first thing you need to do is closely examine the hairs to confirm whether the root is attached or not. If they do, then you need to send a minimum of 4 hairs. To note that the success rate for hair paternity testing is of 60%- this is the probability that the laboratory has of extracting a complete DNA profile from this sample. Ideally, swabs are the best sample to provide or if not possible, than a used Kleenex. A blood DNA test using a medical blood draw is the least recommended- such a sample is tedious to collect and moreover, viewed as “hazardous” unless declared pathogen-free, this means that postage of the sample will be very difficult. 

Pricing Considerations

Non-standard samples in general incur an additional cost to the normal cost of the DNA Paternity test. This reason is normally because the majority of laboratories are set-up to process buccal swabs in bulk. Therefore to process non-standard samples they may have to alter their process which can be much more time and resource consuming.

The cost of these non-standard will vary depending on the type of sample, from one laboratory to another and from one country to another. In addition, in most cases the laboratory will charge for the non-standard sample even if the samples fail to provide any useful DNA.
It is recommended that you request a price quotation from the provider prior to sending any samples. This will give you an idea of the approximate cost of the test.

Legality

The use of non-standard samples is totally legal where consent is obtained. However, in cases where the sample is obtained without consent, different countries have different regulations that apply in such circumstances, although in many countries no actual legislations is in place regulating such activities.

For example, in the United Kingdom it is an offence under section 45 of the Human Tissue Act to have any bodily material with intent to analyse the DNA in it without qualifying consent, subject to certain exceptions. This offence applies to the whole of the UK. In this case, the Client is therefore responsible for ensuring that they are legally entitled to possess and obtain the biological samples passed to the Company for analysis.

However, in many other countries, this situation is not regulated and therefore it is possible to submit such samples for analysis. It is recommended that appropriate legal advice is obtained on this matter prior to submitting any samples.

Packaging

Most non-standard samples can be sent in normal paper or plastic envelopes or sealing bags such as Zip-Lock bags. It is important that certain samples (e.g. toothbrush) are air-dried well. Failure to dry the sample well can result in mould developing in the packaging from the trapped moist air which will degrade the DNA in the sample. In such events, it will be very difficult to obtain suitable DNA to complete the testing. Other material such as liquid blood, sperm, human tissue etc will require specialised packaging. It is advisable to contact the testing company in advance to confirm all packaging arrangements.

General Comments

Technically, any material that contains biological matter on it can be used to obtain a DNA Profile for Paternity testing purposes or other DNA testing services. The usefulness of the sample will depend on number of factors including how much DNA it contains, the age of the sample, whether it has been exposed to contamination or poor storage conditions etc. What is important to highlight is that with non-standard samples there is always a risk that the sample will not work. There is no laboratory that can guarantee 100% in advance that the samples will work since they are not able to determine prior to testing (unless clearly visible such as mould) that there is not enough DNA in the sample.