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 NON STANDARD SAMPLE TESTS |
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List of Non-Standard Samples
Any hair submitted must have roots or the follicle attached. Hair that is cut will not produce significant DNA. When submitting a hair sample, make sure that you do not touch the part with the follicle as much as possible to avoid contamination. The hair can be sent in a normal plastic or paper envelope and marked clearly as a non-standard sample. The lab will normally require a minimum of 6-10 hairs (or as many as possible) although in many cases the client may only have access to one or two hairs. The more the hairs available, the more the chance of obtaining a DNA profile from them. Cigarette butts can be an excellent source of DNA if the sample has not been contaminated by exposure possible contaminating agents. The more the cigarette has been smoked the more DNA is likely to be available. If the cigarette has been shared it is likely that a mixed DNA profile will be obtained in which case more specialised analysis will be required. The client should make sure that the sample is not handled from the end used to inhale the smoke. Ideally the client will submit 2-4 cigarette butts if available. The butt can be sent in a normal plastic or paper envelope and marked clearly as a non-standard sample. A toothbrush can be a good source of DNA if the sample has not been contaminated by exposure possible contaminating agents. The more the toothbrush has been used the more DNA is likely to be available. If the toothbrush has been shared it is possible that a mixed DNA profile will be obtained in which case more specialised analysis will be required. The client should make sure that the sample is not handled from the end of the bristles to avoid contamination. Also the brush should be air dried for about 30-60 minutes to ensure that it is properly dried before sending to the laboratory. The toothbrush can be sent in a normal plastic or paper envelope and marked clearly as a non-standard sample. Blood Blood samples can take various forms including whole blood, blood spots on paper or other material (tissues, clothing, and furniture), dried blood etc. Blood used to be the most common form of submitting DNA samples for DNA Paternity Testing until the advent of buccal swabs. It now rarely requested as it is invasive as opposed to the non-invasive and painless nature of a buccal swab. Fresh blood sent in a normal tube will provide a very good sample for obtaining DNA although in such a case if the person is available for taking blood a buccal swab is recommended instead. In, cases where blood is sent as spots on some form of material, then the success of the extraction will depend on the state of the blood and whether it has been exposed to possible contamination such as the elements, cleaning agents or other chemical agents. Envelope And Stamp Licked envelopes and stamps can provide a source of DNA for paternity testing purposes. However, there is greater risk of obtaining no DNA since it is not always possible to know if the stamp and envelope have been licked or not. In cases where there has been no contact with a person’s saliva then it is clearly not possible to obtain DNA. In addition, the sticking agent can inhibit the collection of the DNA at the laboratory. Because of this, at easyDNA we classify this type of sample with a Low success rate although with good quality samples it has not been a problem to obtain clear and clean DNA profiles to be used for DNA Paternity Testing purposes. When submitting the sample, the Client should ensure not to touch the seals and the back of the stamp to minimise possible contamination. It is also possible to extract DNA from Nails. Freshly trimmed nails work best and have the highest chance of success. Nails are normally recommended (apart from hair) in cases where the person has recently died and a sample for DNA profiling is required. It is important to minimise the direct contact with the nails as much as possible to avoid possible contamination. The nails can be sent in a normal plastic or paper envelope and marked clearly as a non-standard sample.
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to top Chewing gum can be a good source of DNA if the sample has not been contaminated by exposure possible contaminating agents. Sugar free gum is preferred to normal type of gum. It is important to try not to touch the gum with the fingers as this can lead to contamination. The gum can be sent in a normal plastic or paper envelope and marked clearly as a non-standard sample. In the case of liquid semen, it is recommended that the sample is absorbed through a clean cotton swab and air-dried for about one hour. In the case of dried semen stains, either send the material directly to the laboratory or else absorb the stain onto a clean cotton swab moistened with distilled water. Then air-dry for about an hour. The samples can then be sent in sent in a normal plastic or paper envelope and marked clearly as a non-standard sample.
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to top Bone samples are one
of the most difficult materials to obtain DNA from and not all DNA
laboratories offer the service. The success rate will depend on
the condition of the bones (e.g. how long the person has been dead,
how his body has been preserved). When submitting bone samples it
is normally recommend that fragments from the shaft of the femur
or humerus are obtained weighing approximately 2 grams per individual.
We recommend that you contact the laboratory prior to taking the
samples and discuss your case in advance. Collection of samples
should be performed by a qualified person. 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.
These can include toothpicks, used handkerchief/Kleenex, clothing
items (e.g. baseball cap for sweat), dental floss, underwear etc.
The usefulness of the sample will depend on how much DNA it contains,
whether it has been exposed to contamination or poor storage conditions.
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Disclaimer
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