| DNA Paternity testing is the most accurate | | | | samples can then be sent in sent in a normal |
| way of confirming biological relationships | | | | plastic or paper envelope and marked clearly |
| between individuals. The standard way of | | | | as a non-standard sample. |
| collecting samples from the individuals to be | | | | |
| tested is through the use of oral/buccal | | | | Bone |
| swabs. Buccal swabs are relatively easy to | | | | |
| use and pain-free since the procedure | | | | Bone samples are one of the most difficult |
| involves simply rubbing the swab on the | | | | materials to obtain DNA from and not all DNA |
| inside of the mouth to collect a saliva | | | | laboratories offer the service. The success |
| sample. In addition, they can be easily sent | | | | rate will depend on the condition of the |
| by post to the client when they order a test. | | | | bones (e.g. how long the person has been |
| Hence, they provide an excellent medium to | | | | dead, how his body has been preserved etc). |
| obtain DNA from an individual. | | | | When submitting bone samples it is normally |
| | | | recommend that fragments from the shaft of |
| However, occasions arise when it is not | | | | the femur or humerus are obtained weighing |
| possible to obtain the sample directly from | | | | approximately 2 grams per individual. It is |
| the individual, as for example in the case of | | | | recommended that the laboratory processing |
| a dead or missing person or samples collected | | | | the sample is contacted prior to taking the |
| from a crime scene. Therefore, in such cases, | | | | samples to discuss the case in advance. |
| it is possible to utilise alternative samples | | | | Collection of samples should be performed by |
| (defined as non-standard samples), to obtain | | | | a qualified person. |
| the DNA of a person for the purpose of DNA | | | | |
| Testing. | | | | 2. Everyday items that may contain DNA for |
| | | | testing purposes |
| The following list provides information about | | | | |
| a number of non-standard samples that can be | | | | Cigarette Butt |
| used to obtain DNA for testing purposes. | | | | |
| | | | Cigarette butts can be an excellent source of |
| 1. Direct Biological Samples | | | | DNA if the sample has not been contaminated. |
| | | | The more the cigarette has been smoked the |
| Hair | | | | more DNA is likely to be available. If the |
| | | | cigarette has been shared it is likely that a |
| Any hair submitted must have roots or the | | | | mixed DNA profile will be obtained, in which |
| follicle attached. Hair that is cut will not | | | | case more specialised analysis will be |
| produce significant DNA. When submitting a | | | | required to separate the profiles. The client |
| hair sample, one must make sure not to touch | | | | should make sure that the sample is not |
| the part with the follicle as much as | | | | handled from the end used to inhale the |
| possible to avoid contamination. The hair can | | | | smoke. Ideally the client will submit 2-4 |
| be sent in a normal plastic or paper envelope | | | | cigarette butts if available. The butt can be |
| and marked clearly as a non-standard sample. | | | | sent in a normal plastic or paper envelope |
| The lab will normally require a minimum of | | | | and marked clearly as a non-standard sample. |
| 6-10 hairs (or as many as possible) depending | | | | |
| on what is available. The more the hairs | | | | Toothbrush |
| available, the more the chance of obtaining a | | | | |
| DNA profile from them. | | | | A toothbrush can be a good source of DNA if |
| | | | the sample has not been contaminated. The |
| Blood | | | | more the toothbrush has been used the more |
| | | | DNA is likely to be available. If the |
| Blood samples can take various forms | | | | toothbrush has been shared it is possible |
| including whole blood, blood spots on paper | | | | that a mixed DNA profile will be obtained in |
| or other material (tissues, clothing, and | | | | which case more specialised analysis will be |
| furniture), dried blood etc. Blood used to be | | | | required. The client should make sure that |
| the most common form of submitting DNA | | | | the sample is not handled from the end of the |
| samples for DNA paternity testing until the | | | | bristles to avoid contamination. Also the |
| advent of buccal swabs. It now rarely | | | | brush should be air dried for about 30-60 |
| requested as it is an invasive procedure as | | | | minutes to ensure that it is properly dried |
| opposed to the non-invasive and painless | | | | before sending to the laboratory. The |
| nature of a buccal swab. Fresh blood sent in | | | | toothbrush can be sent in a normal plastic or |
| a normal tube will provide a more than enough | | | | paper envelope and marked clearly as a |
| sample for obtaining DNA. In cases where | | | | non-standard sample. |
| blood is sent as spots on some form of | | | | |
| material, then the success of the extraction | | | | Envelope and Stamp |
| will depend on the state of the blood and | | | | |
| whether it has been exposed to possible | | | | Licked envelopes and stamps can provide a |
| contamination such as the elements, human | | | | source of DNA for paternity testing purposes. |
| contamination and/or chemical agents. | | | | However, the success rate on this type of |
| | | | sample can very widely since it is not always |
| Nails | | | | possible to know if the stamp and envelope |
| | | | have been licked or not. In cases where there |
| It is also possible to extract DNA from | | | | has been no contact with a person's saliva |
| Nails. Freshly trimmed nails work best and | | | | then it is clearly not possible to obtain |
| have the highest chance of success. Nails are | | | | DNA. Because of this, the sample is normally |
| normally recommended (apart from hair) in | | | | classified as having a low rate of extraction |
| cases where the person has recently died. It | | | | success rate. When submitting the sample, it |
| is important to handle the nails with minimal | | | | is important to ensure not to touch the seals |
| direct contact as possible to avoid | | | | and the back of the stamp to minimise |
| contamination. The nails can be sent in a | | | | possible contamination. |
| normal plastic or paper envelope and marked | | | | |
| clearly as a non-standard sample. | | | | Chewing Gum |
| | | | |
| Sperm | | | | Chewing gum can be a good source of DNA if |
| | | | the sample has not been contaminated by |
| In the case of liquid semen, it is | | | | exposure to contaminating agents. Sugar free |
| recommended that the sample is absorbed | | | | gum is preferred to normal type of gum. It is |
| through a clean cotton swab and air-dried for | | | | important to try not to touch the gum with |
| about one hour. In the case of dried semen | | | | the fingers as this can lead to |
| stains, either send the material directly to | | | | contamination. The gum can be sent in a |
| the laboratory or else absorb the stain onto | | | | normal plastic or paper envelope and marked |
| a clean cotton swab moistened with distilled | | | | clearly as a non-standard sample. |
| water. Then air-dry for about an hour. The | | | | |