Deoxyribonucleic acid, better known as DNA, is what makes up your biological self. DNA can also provide information about your health, growth, and aging.
Given the increase in at-home DNA testing kits — typically done with saliva samples — many wonder whether home urine testing could offer the same results.
Urine does contain small amounts of DNA, but not nearly as much as blood or saliva. DNA also deteriorates more quickly in urine, making it difficult to extract and produce reliable test results.
Keep reading to learn more about the DNA in your urine, and what clues it can offer to your overall health.
DNA is made up of nucleotides, including 2-deoxyribose, nitrogen bases, and phosphate groups.
The exact markers in each strand of DNA are measured through the blood with the help of white blood cells and epithelial cells, which are found in the surface layers of your skin. In addition to blood, DNA can also be found in saliva, hair follicles, and decomposing bones.
While DNA can be found in urine, it’s directly related to the presence of epithelial cells, and not the urine itself. In fact, DNA can often be better detected in female urine because women may have higher epithelial cell counts that enter their urine from vaginal walls.
It’s difficult to detect DNA in urine. Low white blood cell and epithelial cell counts can affect DNA in the urine. DNA can also deteriorate quicker in urine, making it more challenging to extract biomarkers before they lose their integrity.
- First- or second-morning urine may contain the highest yield, and the sample tends to be best preserved at temperatures of -112°F (-80°C). Sodium additives may also be used for further preservation.
- The researchers also found differences in DNA yield based on gender. First-morning urine had the most DNA in males, while afternoon urine produced higher DNA yields in women.
While it’s possible to extract DNA from urine, the conditions aren’t ideal. Other more reliable sources, such as blood, can produce higher yields without the risk of biomarker degradation.
Urine tests may be able to detect DNA fragments, but the results may not be as clear as they could be in blood tests.
Urine samples can, however, be used to detect certain diseases and health conditions, including:
When considering DNA extraction, a urine sample isn’t the best source to use. Blood is the most reliable source of DNA, followed by saliva and hair follicles. If you’re interested in DNA testing, talk to a doctor about these options.
Still, urine samples shouldn’t be disregarded entirely. They can offer clues to your overall health, and may even help your doctor diagnose certain diseases and conditions. As research continues, it’s possible that we will see more urine-based DNA tests in the future.
If you’re suspicious about any potential health concerns, your doctor will likely start with blood and urine tests. If you’re interested in DNA markers for potential future diseases that you may be genetically predisposed to, consider seeing a specialist for a blood test.