I am not an attorney and any comments I post are not intended, nor should they be construed, as legal advice. If you need legal advice, please consult a legal expert who is familiar with the area of legal expertise you need.
I am not a medical health professional and any comments I post are not intended, nor should they be construed, as medical advice. If you believe you are experiencing a medical emergency, dial 911 (where applicable) or contact proper emergency service personnel.
Be aware, in some locations if a person specifically states they do not agree to DNA testing while alive, the restriction remains in place after death. You should your area to see what the law is in those situations. I saw this post back in 2013 from Judy G. Russell, the Legal Genealogist:
As noted, the one exception is where the person, when living, refused to consent to DNA testing. In the organ donation scenario, no means no and if your loved one has a written directive that says no, the law won’t allow the family to override that.3 (And conversely there are now laws in some states that prevent a family from overriding the loved one’s written directive that says yes.4)
Cite/link to this post: Judy G. Russell, “DNA: life after death,” The Legal Genealogist, posted 30 June 2013 (accessed September 21, 2019).
This question, Can DNA Survive Cremation?, was raised in a social media group recently. The standard answer I always heard was NO! and usually stated emphatically as I added it in this sentence. I decided to do some research. The basic answer appears to be that DNA tends to be destroyed if the fire is hot enough, like cremations tend to be. However, there are instances where it may survive. Be aware, that with cremations, any bone or tooth fragments are generally pulverized before the ashes are provided to family.
If you or your loved one is going the cremation route, ask the funeral home or crematorium NOT to pulverize any bone or teeth fragments. Hopefully, they will agree to this option. You might also discuss what options they are really to consider. Some funeral homes will collect DNA samples before starting any process. Ideally, it would be best to see if you get a DNA sample before the process, including embalming if it’s a non-cremation service, starts, but those samples can be hit or miss. Best to get DNA samples as early as possible.
The third article below was done by National Center for Biotechnology Information. It was an eye-opener for me. Note, most of these tests are not doing autosomal DNA for genealogical purposes and are going to be looking at a lot fewer markers and STRs instead of SNPs.
EasyDNA says it can be possible, but the odds of extracting DNA are low: DNA Testing on Cremated remains: https://www.easy-dna.com/cremated-remains-testing/
How is DNA preserved in cremated remains?
Human bones are mainly composed of calcium phosphate and calcium carbonate- these molecules are extremely strong and give bones their characteristic strength and durability. The temperature reached inside the cremation furnace is so high that only bones and teeth are left behind (although even these are altered by the extreme temperature); the rest will be simply ashes which consist of dry calcium phosphates with some minor minerals, such as salts of sodium and potassium. Sulfur and most carbon are lost as gases although a relatively small amount of carbon may remain as carbonate. The actual ashes are thus useless as they will not contain DNA. It is the bones and teeth that could potentially hold some DNA viable for analysis. However, after the cremation, the bones and teeth left behind are turned into a find powder (a process known as pulverization).
Important: The process of pulverization along with the extreme heat the bones are subjected to make extracting DNA a challenge. The chances of successful DNA extraction are low.
The next article addresses Effect of Fire on DNA and its profiling in homicide cases (PDF): https://medcraveonline.com/FRCIJ/FRCIJ-07-00268.pdf. In many cases, the fires won’t reach the temperature levels seen with cremations.
Detection of blood and DNA traces after thermal exposure.: https://www.ncbi.nlm.nih.gov/pubmed/29080916
The analysis of blood traces is often of significant reconstructive and evidence-gathering importance. Perpetrators deliberately set fires to destroy evidence. There is little literature regarding the effect of fire and extreme heat on blood and the detection of blood. Blood and DNA are believed to be no longer traceable after exposure to a temperature of 1000 °C. This study exposed different objects of a standardized procedure to temperatures of 300, 700, and 1000 °C. It documented the influence of heat on blood traces through the use of luminol. DNA analysis confirmed that fewer DNA profiles can be created with increasing temperature. However, even after exposure up to a max. of 1000 °C, it was still possible to produce a complete DNA pattern from approx. 60% of the samples. Consequently, crime scenes that have been destroyed by fire should be evaluated with the same attention to detail as the unburned areas.
Past DNA Saturdays posts: https://upsdownsfamilyhistory.wordpress.com/tag/dna-saturdays/