Breast milk can affect a DNA test, but not by altering the DNA itself. Instead, breast milk can contaminate the sample, potentially interfering with the testing process. This contamination stems from the presence of the mother's DNA in the breast milk.
How Breast Milk Can Affect DNA Testing
- Contamination: Breast milk contains the mother's DNA. If a sample (e.g., an oral swab from a baby) is contaminated with breast milk, the lab might detect the mother's DNA alongside the baby's, potentially affecting the accuracy of the results. This is especially true for tests like paternity tests where distinguishing between the child's and mother's DNA is crucial.
- Testing Interference: High levels of contamination may prevent the lab from extracting enough of the target DNA (e.g., the baby's DNA in a paternity test) for accurate analysis. In such cases, the lab may need to request a new, uncontaminated sample.
- No DNA Alteration: It is important to understand that breast milk does not change the genetic information (DNA) itself. The issue lies solely in sample contamination.
Recommendations to Avoid Contamination
- Timing of Sample Collection: For newborns, collecting samples before breastfeeding is crucial to minimizing the risk of contamination. It's generally recommended to wait at least an hour after breastfeeding before taking the sample. This allows for sufficient time for any residual breast milk to be cleared.
- Thorough Cleaning: Ensure the area where the sample is collected is clean and free from any breast milk residue.
Conclusion from Sources
Multiple sources confirm that while breast milk does not alter the DNA itself, it presents a significant risk of contamination, potentially disrupting DNA testing accuracy. The labs involved will typically request new samples to ensure reliable and accurate results if contamination is detected. Proper sample collection techniques are therefore essential to avoid this issue.