The Tiniest Sample for a DNA Test
DNA is present in every cell of our bodies. Therefore, laboratories and clinics don’t need a huge sample in order to isolate each individual’s DNA. Provided the sample isn’t contaminated, even the smallest sample can hold the information you need.
Giving a DNA Sample
Although DNA can be extracted from tiny samples, a larger sample will be more useful in the long term. Even so, when you are sent a sample kit by post, you still only need to provide a relatively small sample – just some cells from the inside of your cheek transferred onto a swab. You’ll find, however, that there are specific instructions to ensure that you collect as many cells as possible so that the laboratory has a good sample to work with.
The Accuracy of DNA Testing
Even based on a tiny sample, DNA testing can be accurate enough to tie people to the scene of a crime, establish familial relationships, or even investigate the ethic origins of archaeological remains. The number of incidents where DNA testing has proved the turning point is increasing – here are just a few examples:
- Inca sacrifice – In the 1990s the frozen remains of an Inca human sacrifice was found on Mount Ampato in Peru. Estimated to be around 500 years old, the girl, who was no older than 14 when she died, has been incredibly well-preserved. A DNA analysis and sequencing could identify her mitrochondrial DNA, which in turn could identify living Peruvians who may be related to her.
- Plant DNA solves murder – The first case of plant DNA analysis contributing to a murder conviction came from the site of a murder in Arizona. Pods found in a suspect’s truck were successfully shown to only come from a tree near the scene which showed signs of vehicle damage.
- Proving innocence – Testing is often used to eliminate people from an investigation – but for those who were tried and convicted before DNA testing became routine, and who are innocent, this is cold comfort. If case files include relevant samples of DNA, further testing could prove innocence and allow those falsely accused to resume a normal life.
