The standard source of DNA material needed to perform a genetic paternity test is a swab on the inside of the cheek. However, this test can also be carried out using, for example, hair with roots, sperm, a used toothbrush or a razor.

Cheek swab - standard source of DNA material

Virtually every ID laboratory usesinner cheek swab(inner mouth swab) as standard material. This is because it usually contains a very large amount of DNA. During the collection of this type of sample, a special stick is rubbed on the cheek from the inside, thanks to which epithelial cells can be collected, which are an excellent source of a person's genetic material. Correctly performing this operation ensures that there is enough DNA on the swab, which can be successfully used inpaternity test .

The advantage of a cheek smear is, firstly - the possibility of self-collection of samples at home, and secondly - possible blood transfusions that the patient has undergone should not affect the credibility of the result. It is also worth mentioning that almost every genetic laboratory recommends taking cheek swabs due to the fact that they have research methods adapted to work with swabs.

What types of samples can be used in the paternity test?

Although a cheek swab is a very good source of genetic material, it must be clearly stated that obtaining it does not allow for complete discretion. However, there are cases where, for various reasons, it is not possible to take a smear from the inside of the mouth. This is not only about the situations where the sample is taken "ste althily", but about the cases where one of the test subjects is dead, but there are still items of personal use that could potentially contain DNA. We are often unaware of the places and circumstances in which we can leave a mark. Starting with the fragments of the epidermis that are invisible to the naked eye, and ending with blood stains of various origins. So, what other types of samples can be used in the paternity test? In professional practice, we most often deal withwith the following materials:

  • hair with roots - it is important that the hair has the roots that are visible to the naked eye. They cannot be cut, but torn out, because DNA is isolated from fragments of the epidermis surrounding the hair bulb;
  • blood stains - this is a classic material containing a potentially large amount of DNA. The stain can be left on a handkerchief, clothing, various kinds of items or even on food;
  • toothbrush - used many times by only one person, it is an excellent source of DNA. Unfortunately, due to the fact that the brushes of the whole family are quite often located in one place, there is a potential risk of using the toothbrush from the wrong person;
  • razor - the razor collects epidermis containing a large amount of DNA during shaving;
  • semen or sperm stains - often, dry sperm stains are left on the underwear, from which male DNA can be easily isolated. The so-called "Fresh" sperm sealed in a condom, allowing you to successfully obtain a complete male profile. The sperm residue is also used in another type of test that many laboratories refer to as "betrayal tests". After sexual intercourse, a male-female DNA mixture may potentially remain on the underwear, bedding, etc. An experienced geneticist, having at his disposal the reference material of one of the people, is able to determine who the person whose DNA is in the mixture of genetic profiles;
  • chewing gum - chewing gum for a few minutes enriches it with our DNA, hence it can be used as a potential source of research material;
  • nails - deeply cut or containing cuticle fragments;
  • handkerchief with nasal discharge - mucus from the nose in a cold person can be subjected to DNA isolation. It is worth paying attention to the fact that the handkerchief is not soiled with food or makeup remnants and that it does not contain fragrances.

The above types of material are most often used in paternity tests or for personal identification. They potentially contain large amounts of DNA, and as long as the sample is not contaminated and the DNA itself is not degraded, then the sensitivity of the test is the same as if the test was performed with a smear on the inside of the cheek. In such situations it is taken into account that the DNA is the same regardless of the place of isolation. Regardless of whether the examination is performed on the basis of a cheek swab, blood spots or hair with roots, the result should beidentical (regardless of the material used).

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Research