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