蛋白酶-过氧化氢消解法在法医学硅藻检验中的应用

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

目的 提出一种新型法医学硅藻检验方法,即蛋白酶-过氧化氢(protease-hydrogen peroxide,PHP)消解法,探讨该方法在法医学鉴定实践中的应用潜力。方法 应用PHP消解法对肺组织进行处理并在硅藻数量、硅藻回收率、硅藻碎片占比以及不同硅藻科属回收效能等方面与传统的硝酸破机法进行比较。结果 PHP消解法在硅藻数量、硅藻回收率以及硅藻碎片占比方面均高于传统的硝酸破机法且差异具有统计学意义,平均硅藻回收率高达93.95%。硝酸消解后的肺组织中曲壳藻属(65个)、菱形藻属Ⅰ(36个)、菱形藻属Ⅱ(22个)、双壁藻属(20个)、桥弯藻属(8个)均低于提取水样(曲壳藻属154个、菱形藻属Ⅰ44个、菱形藻属Ⅱ45个、双壁藻属33个、桥弯藻属23个),而PHP消解法仅菱形藻属Ⅱ低于提取水样(P<0.05),同时其硅藻回收稳定性方面高于硝酸破机法。结论 PHP消解法在肺组织硅藻提取效能方面优于传统的硝酸破机法,且在安全、环保等方面具有较大的优势,有望应用于溺死鉴定实践。

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 prac‐tice.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 tra‐ditional 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 NitzschiaⅠ,22 NitzschiaⅡ,20 Diploneis and 8 Cymbella,showing significantly lower recovery rates compared to water samples which had 154 Achnanthes,44 NitzschiaⅠ,45 NitzschiaⅡ,33 Diploneis and 23 Cym‐bella.However,with the PHP digestion method,only NitzschiaⅡshowed a lower recovery rate com‐pared to water samples(P<0.05).At the same time,the diatom recovery stability of the PHP diges‐tion 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 as‐pects.It is expected to be applied in forensic drowning identification.