A Reddit message made a big splash on the internet this week when it claimed that the infamous, $ 30 "GamerGirl bath water" sold by social media star Belle Delphine contained no human DNA – and therefore maybe not her bath water at all. This was promptly challenged by other Reddit users and debunked: the shipments of that bath water had not even been broadcast yet. When the news of the non-scandal went around The edge offices, reporters started pelting the scientific desk with questions, including; "Wait, you can test bath water for DNA?"
"Yes, you can," says forensic biologist Helen Page. Page is an associate professor at Teesside University in the UK, and has actually studied how very specific DNA examples can be found from a bath.
It is serious work. Recovering DNA from a shower or bath can be useful during an assault investigation, especially if a victim does not want to undergo a full forensic investigation or is showered after the assault. Page has investigated how sperm can be recovered specially designed mesh objects made to fit in shower drains, and "bad scrunchies"(Also known as sponges, loofah & poufs). She discovered that you can recover DNA from gauze, from scrunchies, and also simply by sweeping along the walls, base and drain of a bath.
Page has shown that it is possible to recover DNA from sperm in bath water, but sperm is very different from other cells. "The structure of a sperm is, as it were, quite resistant to degradation in the same way that other cells would be," says Page. In the case of Delphine, the most likely source of DNA would be a skin that can be drained into the bath. Page's research was also conducted in the laboratory under controlled conditions. In the case of the & # 39; GamerGirl Bathwater & # 39; without seeing the production process, there really is no way to know how much of Delphine's DNA has completely taken into the water.
"It's hard to know how many cells would have been fired in the washing process," says Page. She points out that if Delphine were to wash lightly, fewer skin cells would be released than if they were washed more thoroughly. "I very much doubt that there will be an enormous amount of DNA in a small tube of the bath water," says Page.
It is not clear how long DNA would continue to exist in bath water. The greatest threats to DNA integrity are abundance of heat, moisture and bacteria. Soap and other cleaning products can also play a role in breaking down DNA, but there is not enough scientific research available to know for sure.
Even if there is enough DNA in the water for testing, and you have the right laboratory equipment and it is not degraded, an analysis can show whether or not a person is human, and not which person is bathed in it. "You couldn't say it was her DNA unless you had her DNA profile to compare with." Says page.
All this of course only answers the question of whether or not people could should – test a $ 30 bath of DNA bath water in the first place. Why it is sold, however, is clear: as Patricia Hernandez points to Polygon, Delphine is known for performance-worthy stunts.
Although Page emphasizes that she would not spend her money on bath water, she does understand why people want to verify their purchase. "If I would pay so much money for some of the water that Person X had swum into," says Page, "I would like Person X to have the bath water sprayed in."