Do We Have DNA in Nails?
Yes, fingernails and toenails contain DNA. While primarily composed of keratin, a protein, nails contain DNA from the skin cells surrounding the nail bed. This DNA can be extracted and used for various purposes, including forensic investigations and genetic studies.
Multiple studies have demonstrated the successful extraction of DNA from nail clippings. One study found that an average of 6.3 milligrams of nail yielded an average of 544 ng DNA, or 91.7 ng/mg of nail. These results, however, varied depending on the method used for measurement (NanoDrop vs. PicoGreen). [^1] The process involves careful collection and processing of nail clippings to maximize DNA yield and minimize contamination. Several commercial DNA testing companies offer services using nail clippings as a sample source. [^8]
Advantages of Using Nails for DNA Analysis
Nail clippings offer several advantages as a source of DNA:
- Easy Collection: Nails are easily collected and stored, making them a convenient sample type for large-scale studies. [^3, ^9]
- Autologous Germline DNA: Fingernails provide purely autologous germline DNA, meaning the DNA is solely from the individual and not a mix of cells. [^4]
- Accessibility: Nails are readily accessible, even in situations where other tissue samples may be difficult to obtain. [^5, ^10]
Applications of Nail DNA Analysis
Nail DNA analysis finds applications in various fields:
- Forensic Science: Fingernail material serves as an important source of DNA in forensic investigations. [^6, ^7] DNA under fingernails can provide crucial evidence linking suspects to a crime. [^7]
- Genetic Studies: Nails can be used in large-scale epidemiologic studies requiring genetic analysis. [^3, ^9]
- Relationship Testing: Commercial DNA testing companies utilize nail clippings for paternity and kinship testing. [^8]
[^1]: Human Nail Clippings as a Source of DNA for Genetic Studies. https://pmc.ncbi.nlm.nih.gov/articles/PMC4499506/
[^3]: DNA from Nails for Genetic Analyses in Large-Scale Epidemiologic Studies. https://aacrjournals.org/cebp/article/23/12/2703/115792/DNA-from-Nails-for-Genetic-Analyses-in-Large-Scale
[^4]: Regular article High-Quality DNA from Fingernails for Genetic Analysis. https://www.sciencedirect.com/science/article/pii/S1525157814000671
[^5]: Trace DNA from Fingernails: Increasing the Success Rate of Widely Used Collection Methods. https://www.ojp.gov/pdffiles1/nij/grants/249534.pdf
[^6]: Do Nails Have DNA: How Does a Nail DNA Test Work? https://dnacenter.com/blog/do-nails-have-dna-how-does-a-nail-dna-test-work/
[^7]: DNA under fingernails? : r/JusticeForKohberger https://www.reddit.com/r/JusticeForKohberger/comments/1auz67k/dna_under_fingernails/
[^8]: Nail DNA Testing | AlphaBiolabs USA https://alphabiolabsusa.com/dna-test-kit/nail-clipping-dna-relationship-test/
[^9]: DNA from nails for genetic analyses in large-scale epidemiologic ... https://pubmed.ncbi.nlm.nih.gov/25472680/
[^10]: Do nails contain DNA? - Quora https://www.quora.com/Do-nails-contain-DNA
