We’re all familiar with DNA evidence being collected from crime scenes. Whether it’s on NCIS, CSI or Dexter, a crime scene investigator’s role is to collect and preserve any samples of skin, hair or bodily fluid. This is because blood, skin, saliva, sweat, urine, semen and hair can readily provide DNA information, which can hopefully lead to a crime being solved and the perpetrator being brought to justice.
This process is formally termed DNA profiling, and involves the lengths of variable sections of repetitive DNA, such as short tandem repeat (STR) markers, being compared between people. These STR markers are highly variable in length between individuals, which makes DNA testing the most scientific and accurate way to identify someone. The technique of DNA profiling was developed in 1984 by British geneticist Sir Alec Jeffreys, and was first used to gain a successful conviction in 1988.
Today, DNA testing is accessible to everyone around the world. Hundreds of thousands of people use mail order tests to prove that two or more individuals are biologically related. The range of DNA relationship tests that can be undertaken include paternity, maternity, grandparent, aunt or uncle, twin, and Y chromosome. Thankfully, there is no need to collect blood or other dubious bodily fluids. Nowadays, individuals simply need to swab the inside of their cheeks to provide a sample of buccal cells for DNA analysis. The process is very simple and painless, which lends itself to home testing. Full instructions are included in the kits mailed out and the individuals collect their own samples. These samples are then mailed back to the DNA testing laboratory for analysis. Results are made available within days.
So far so good. A DNA test can now be initiated without having to leave your home. DNA testing has certainly become much more accessible and user-friendly. And yet, using a mouth swab on an individual to collect their cheek cells is not something that can be done surreptitiously.
Toothbrush and nail clipping DNA analysis
Help is at hand. Sample collection too has been made more accessible (and discreet) thanks to DNA testing further evolving. AlphaBiolabs’ scientists have established that both toothbrushes and nail clippings are good sources of DNA. The toothbrushes need to be used, and not cleaned, before being sent to the laboratory. The dry toothbrush can be sent in for analysis. The heads of electric toothbrushes can also be accepted.
For nail clipping DNA analysis, both toe nails and finger nails can be used. As many nail clippings as possible are required as this provides more sample to be analyzed. The advantage of using toe nails over finger nails is that there is less potential for contamination. However, acrylic nails, Shellac and other forms of nail polish may need to be removed as this may impact on the DNA results.
When the toothbrush or nail clippings are received at the laboratory, a viability study is initially performed to ascertain whether a DNA profile can be extracted from the sample. If a DNA profile can be extracted, any DNA relationship test can then be performed. The profile will be analyzed for up to 35 STR markers, making it one of the most accurate DNA tests on the market.
Relationship tests are completed by comparing the observed DNA profiles from a group of people and considering the probability of any potential relationships. Paternity tests, for example, are completed by comparing the STR markers seen in the child with those seen in the alleged parents.
Advantages of toothbrush and nail DNA testing
A major advantage of toothbrush and nail clipping DNA tests is that samples can be collected in a more subtle manner. For example, children don’t need to be made aware that a test is being undertaken. This would be particularly beneficial in the case of a paternity dispute, where using a mouth swab on older children could lead to awkward questions. Simply sending in their regular toothbrush or nail clippings instead allows for more discreet sampling.
It is important to note that consent is needed for anyone supplying their DNA for testing. Anyone over the age of 16 would have to sign their own consent, but a parent or guardian with parental responsibility could sign on behalf of a child undertaking DNA testing. This makes toothbrush and nail clipping DNA analysis particularly beneficial when there is a need to DNA test children without alerting them to the situation.
Another application of nail DNA testing is when an individual has passed away. This is in the event of the mouth swab method of DNA collection not working. Consent would be needed from the next of kin or another qualifying relative to process a deceased individual’s nail sample. As well as proving a biological relationship, the DNA profile produced by the nail DNA test could be made into a lasting memento of a loved one.
DNA technology has evolved vastly over the last 30 years. Toothbrush and nail clipping DNA analysis are two of the latest tools to revolutionize the DNA testing market and help people answer their relationship queries.