Photo credit: micromagus.net
Diatoms are a prominent group of microflora, abundantly present in freshwaters and marine habitat. I feel diatoms would be the formidable contenders, if anytime we plan on hosting a beauty pageant in the waters, across the globe. They are one of a kind-with their cell walls composed of transparent, opaline silica, giving them a vibrant look. As a matter of fact, back in the 1800s, art was made using diatoms by arranging them in beautiful patterns.
Besides the attractive appearance and texture, they are ecologically significant. These single-celled microscopic algae contribute to the world's 20% oxygen. We might wonder, how can a microscopic organism be responsible for such enormous productions of oxygen? It is possible because they are photosynthetic, like plants. They dominate the aquatic biomass because of their colonial presence. Their diversity is unmatched and thus Diatoms are of paramount importance in Forensics.
The interesting fact is that in drowning cases, the challenge to any investigator is to conclude if the demise happened before or after drowning. Now that we know diatoms have application in solving Forensic issues, the underlying mechanism is simple. If the person is alive, then he/ she will gulp and inhale a certain amount of water into the body. Along with water, diatoms too will make their way into the body. The first destination of diatoms is the lungs. From there, via systemic circulation [blood], they’ll deposit onto various organs like the liver, kidney, and even the bone marrow. In the opposite scenario: there would be no life, no circulation, and no diatoms lodged in the internal organs.
Since diatoms are acid-resistant, these samples can be isolated using acid-digestion methods. But due to associated drawbacks, Scanning electron microscopy [SEM] and DNA sequencing methods are employed to achieve rapid and accurate results. However, affording such expensive equipment at every forensic centre will be a nightmare. Recent reports state implementing deep learning [an artificial intelligence domain] to identify diatoms has been in the plans. An automated and smarter approach for morphological testing of diatoms can reduce the loss of samples and time.
Research is dynamic, but with the advent of technology, the research practices are transforming. Already the lines are blurring between various disciplines. A trans-disciplinary and holistic approach is an answer to all the problems we will be tackling in the future. Today diatoms are solving the mysteries of death. Who knows what other challenges diatoms can help us solve in the future?
Article by,
Meghna Girish
Content Writer
Treillis Life Sciences Pvt. Ltd.
References
Kaushik N, Kumar-Pal S, Sharma A, Thakur G. Role of Diatoms in Diagnosis of Death Due to Drowning: Case Studies. International Journal of Medical Toxicology and Forensic Medicine. 2017; 7(1): 59-65.
Kaye, T. G., & Meltzer, M. (2020). Diatoms constrain forensic burial timelines: a case study with DB Cooper money. Scientific reports, 10(1), 13036. https://doi.org/10.1038/s41598-020-70015-z
Malviya, S., Scalco, E., Audic, S., Vincent, F., Veluchamy, A., Poulain, J., ... & Zingone, A. (2016). Insights into global diatom distribution and diversity in the world’s ocean. Proceedings of the National Academy of Sciences, 113(11), E1516-E1525.