What can DNA testing be used to prove relationships (father-mother-child, siblings)?
Hair, nails, toothbrushes, etc.

How to collect DNA to prove relationships according to standards

DNA testing to prove blood kinship, whether it be father, mother, child, sibling, or grandparent, is the best and most painless method. DNA is collected from buccal cells using a DNA collection device, a stick with a polyester tip, applied to the inside of both cheeks in the mouth. This method of testing requires the consent of the person being tested.

In cases where DNA collection from buccal mucosal cells is not desired, can the specimen be collected from another source?

We can also collect other specimens containing a person’s DNA for testing. However, the individual who wishes to know must collect the specimens themselves, and our company will not be aware of how the specimens were collected or whether they actually came from that individual. Therefore, the results report will not include the name and surname of the person being tested. Instead, it will only state whether the two specimens are genetically related.

What specimens can be tested for DNA to prove kinship?

Anything containing a person’s cells can be sent for DNA testing. However, extracting DNA from each specimen can vary in difficulty, resulting in varying success rates. Details are as follows:

 

 

Types of samples that can be sent for DNA testing to prove relationship

Success rate: 90% or higher

• Semen (Whole Semen)¹
  • Frozen semen (semen bank), fresh semen on a cotton swab, or fresh semen on tissue.
• Saliva (Whole Saliva)
  • Store in a sample tube containing preservative.
• Whole Blood
  • Store in a vacuum tube with a purple cap (EDTA tube).
• Blood/Saliva on Filter Paper
  • Filter paper, parchment paper, should be no more than 60 days old.
• Bone marrow
  • Fresh or frozen samples – not on slides or in paraffin.
• Mucus/Sputum
  • It is usually found on tissue paper, handkerchiefs or napkins.
• Toothbrush
  • Leave to dry for at least 30 minutes before sending for examination.

Success rate: 60% to 90%

• Blood Stain on Fabric
  • They are usually found on gauze, tissues, napkins, or clothing.
• Semen stain on fabric¹
  • It is usually found on gauze, tissues, or clothing (indicate the area with the stain).
• Saliva Stain on Fabric
  • It is usually found on gauze, tissues, or clothing (indicate the area with the stain).
• Unknown Stain on Fabric
  • Biological stains of unknown origin (specify the area where the stain is present)
• Fingernail/Nail Clippings
  • Collect 5-10 samples.
• Diabetic Test Strips
  • Collect multiple strips of samples
• Ear swab
  • Use a cotton swab or Q-tip.
• Umbilical cord
  • Should be a dry sample (must have a reference sample from the mother)
• Cigarette Butts
  • Several samples of cigarette butts
• Sanitary napkins/pads (Tampon/Feminine Pad)¹
  • Note: DNA may not be extracted.
• Drinking Straw
  • Leave to dry before packing.
• Dental Floss
  • Do not touch dental floss with your fingers.
• Serum
  • At least 200µl of the extract is sent frozen.
• Muscle/Organ Tissue
  • Fresh or frozen samples are preferred.
• Samples from fetal demise
  • Must have a reference example from the mother

Success rate: 60% or less

• Hair
  • There must be hair roots attached. It is recommended to collect 7-10 hairs as a sample.
• Razor (Razor – electric or disposable)
  • Send a sample of the blade with hair debris.
• Comb/Brush
  • Send samples of both combs and brushes that contain hair debris.
• Chewing Tobacco
  • Packed in a sealed plastic bag, it should have a shelf life of no more than 3 days.
• Jewelry
  • Such as rings, watches, necklaces, etc.
• Chewing Gum
  • It should be sugar-free gum.
• Soda Can/Drinking Glass
  • Sending the can or glass directly is better than collecting the sample yourself.
• Clothing
  • Such as hats, headbands, scarves
• Envelope Flaps/Stamps
  • Envelopes or stamps that have been licked before sealing
• Condoms¹
  • Send the whole condom, test both inside and outside.
• Paraffin Embedded Tissue
  • Tissue samples in paraffin blocks or on slides

Success rate: Unable to assess (N/A)

• Teeth
  • Introducing a sample molar tooth
• Bone
  • Introduce examples of femur, humerus, or thumb bones.
• Feces
  • Packed in a sealed plastic bag, sent in a cool or dry container.

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note:
¹ Separate DNA extraction is recommended for samples containing mixed male and female DNA (e.g., semen).

Benefits of self-collection

HealthSmile can offer DNA testing using specimens other than buccal swab DNA. The specimens must be collected by the test recipient themselves, and the results will not be anonymous, as we cannot confirm who the specimens came from. However, collecting specimens to prove blood relationship on your own has several advantages, including:

• Convenience
  • Samples can be collected at home or at a convenient location without having to travel to a clinic or lab.
  • Simplify the appointment and waiting process
  • Flexible timing, samples can be collected at any convenient time.
• privacy
  • Self-sampling allows stakeholders to act without disclosing information to outsiders.
  • Ideal for situations where confidentiality and privacy are required.
  • Suitable for people who do not want others to know that they intend to undergo an examination.
• Easy to use
  • Most DNA test kits are designed to be easy to use, with clear instructions.
• Collection of diverse samples
  • Appropriate samples such as saliva, hair, nails, toothbrushes, etc. can be selected depending on the situation and convenience.
• Suitable for preliminary testing
  • Suitable for those who want results for family use, such as building confidence in relationships, or in cases where legal consequences are not desired.

Example cases where DNA should be collected to prove blood relationship and sent for self-testing

1. In cases where people want maximum privacy, do not want to provide personal information, or do not want to meet with any officials or personnel in order to protect their privacy.
   • HealthSmile is happy to provide contact information as an anonymous or fictitious name.
   • HealthSmile delivers test kits to recipients in a sealed box. The recipient will not know what’s inside until they open the box.
2. In cases where some persons who need to undergo the examination do not consent to the examination, such as the suspected father refusing to undergo the examination or the mother of the child refusing to allow the examination, the company will not be able to provide the service. Therefore, both persons receiving the service must make an agreement among themselves and collect the items sent for examination themselves.
   • HealthSmile will send you the test kit first. You only pay for the kit and shipping cost of 500 baht. If an agreement is reached, you will collect the specimen and return it to our center, which will check its quality before sending it abroad. If the specimen meets the standard criteria for sending it, you will then pay the remaining cost.
     • Reduce the cost problem in case of failure to reach an agreement
     • Reduce family worries by not having to pay a lump sum at once.
3. In the case where the examinee is in different locations
   • The HealthSmile DNA paternity test kit can be stored for up to 30 days (but it is recommended that you collect the samples within 7 days of each other). Therefore, even if you are in different locations, you can collect the samples one by one without rushing.