Evaluation of three methods for forensic diatom test
10.3969/j.issn.1673-4254.2015.03.23
- VernacularTitle:三种硅藻检验方法比较
- Author:
Yuzhong WANG
1
;
Jian ZHAO
;
Peng LI
;
Sunlin HU
;
Huipin WANG
;
Huijun WANG
;
Chao LIU
Author Information
1. 南方医科大学基础医学院法医学系
- Keywords:
forensic pathology;
drowning;
diatom test;
microwave digestion;
membrane filtration;
light microscopy
- From:
Journal of Southern Medical University
2015;(3):427-431
- CountryChina
- Language:Chinese
-
Abstract:
Objective To compare the efficacy of three methods for forensic diatom test, namely strong acid digestion-centrifuge enrichment-light microscopy (SD-CE-LM), microwave digestion-membrane filtration-automated scanning electron microscopy (MD-ME-SEM), and microwave digestion-membrane filtration-light microscopy (MD-MF-LM). Methods Sixty samples were randomly divided into 3 groups for diatom test using three methods, and the sample preparation time, degree of digestion and recovery rate of diatoms were compared. Results The sample preparation time was the shortest with MD-MF-LM and the longest with SD-CE-LM (P<0.05). MD-ME-SEM and MD-MF-LM allowed more thorough tissue digestion than SD-CE-LM. MD-ME-SEM resulted in the highest total recovery rate of diatom, followed by MD-MF-LM and then by SD-CE-LM (P<0.05);the recover rate of different diatom species was the highest with MD-ME-SEM, followed by MD-MF-LM and SD-CE-LM (P<0.05). Conclusion SD-CE-LM has a low recovery rate of diatoms especially for those with lengths shorter than 40μm or densities less than 1/5. With a high recovery rate and accuracy in diatom test, MD-ME-SEM is suitable for diagnosis of suspected drowning cases. MD-MF-LM is highly efficient, sensitive and convenient for forensic diatom test.
