Journal of Forensic Medicine ›› 2024, Vol. 40 ›› Issue (4): 317-323.DOI: 10.12116/j.issn.1004-5619.2024.440116

• Original Articles •    

Application of Protease-Hydrogen Peroxide Digestion Method in Forensic Diatom Examination

Wen-qing GUO1,2(), Min CHEN2(), Ao MA2,3, Ping HUANG1,2(), Ji ZHANG2()   

  1. 1.School of Forensic Medicine, Shanxi Medical University, Taiyuan 030001, China
    2.Shanghai Key Laboratory of Forensic Medicine, Key Laboratory of Forensic Science, Ministry of Justice, Shanghai Forensic Service Platform, Academy of Forensic Science, Shanghai 200063, China
    3.Department of Forensic Medicine, School of Basic Medical Sciences, Inner Mongolia Medical University, Hohhot 010110, China
  • Received:2024-01-22 Online:2024-11-08 Published:2024-08-25
  • Contact: Ping HUANG, Ji ZHANG

Abstract:

Objective To propose a novel forensic diatom examination method, namely the protease-hydrogen peroxide (PHP) digestion method, and to explore its potential application in forensic practice. Methods The PHP digestion method was applied to process lung tissues and compared with the traditional nitric acid digestion method in terms of diatom quantity, recovery rate, proportion of diatom fragments, and recovery efficiency of different diatom genera. Results The PHP digestion method showed higher diatom quantity, recovery rate, and proportion of diatom fragments compared to the traditional nitric acid digestion method with statistical significance. The average diatom recovery rate was as high as 93.95%. In the lung tissues digested with nitric acid, there were 65 Achnanthes, 36 Nitzschia Ⅰ, 22 Nitzschia Ⅱ, 20 Diploneis and 8 Cymbella, showing significantly lower recovery rates compared to water samples which had 154 Achnanthes, 44 Nitzschia Ⅰ, 45 Nitzschia Ⅱ, 33 Diploneis and 23 Cymbella. However, with the PHP digestion method, only Nitzschia Ⅱ showed a lower recovery rate compared to water samples (P<0.05). At the same time, the diatom recovery stability of the PHP digestion method was higher than that of the nitric acid digestion method. Conclusion The PHP digestion method is superior to the traditional nitric acid digestion method in the lung tissue diatom extraction efficiency. Additionally, it holds significant advantages in safety, environmental protection, and other aspects. It is expected to be applied in forensic drowning identification.

Key words: forensic pathology, death from drowning, diatom examination, protease-hydrogen peroxide digestion method

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