title: [Evaluation of three methods for forensic diatom test].
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).
  
  
  CONCLUSIONS
  SD-CE-LM has a low recovery rate of diatoms especially for those with lengths shorter than 40 µm 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.
authors.affiliation: Department of Forensic Medicine, Southern Medical University, Guangzhou 510515, China.E-mail: 519720474@qq.com.
authors.forename: Yuzhong
authors.initials: Y
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Zhao
authors.forename: Peng
authors.initials: P
authors.lastname: Li
authors.forename: Sunlin
authors.initials: S
authors.lastname: Hu
authors.forename: Huipin
authors.initials: H
authors.lastname: Wang
authors.forename: Huijun
authors.initials: H
authors.lastname: Wang
authors.forename: Chao
authors.initials: C
authors.lastname: Liu
mesh_terms: D002498:Centrifugation; D017377:Diatoms / Q000302:isolation & purification*; D004332:Drowning; D044707:Forensic Sciences / Q000379:methods*; D006801:Humans; D008853:Microscopy; D008855:Microscopy, Electron, Scanning; D008872:Microwaves; D013048:Specimen Handling