[Comparative analysis between diatom nitric acid digestion method and plankton 16S rDNA PCR method].
OBJECTIVE
To compare and explore the application value of diatom nitric acid digestion method and plankton 16S rDNA PCR method for drowning identification.


METHODS
Forty drowning cases from 2010 to 2011 were collected from Department of Forensic Medicine of Wenzhou Medical University. Samples including lung, kidney, liver and field water from each case were tested with diatom nitric acid digestion method and plankton 16S rDNA PCR method, respectively. The Diatom nitric acid digestion method and plankton 16S rDNA PCR method required 20 g and 2 g of each organ, and 15 mL and 1.5 mL of field water, respectively. The inspection time and detection rate were compared between the two methods.


RESULTS
Diatom nitric acid digestion method mainly detected two species of diatoms, Centriae and Pennatae, while plankton 16S rDNA PCR method amplified a length of 162 bp band. The average inspection time of each case of the Diatom nitric acid digestion method was (95.30 +/- 2.78) min less than (325.33 +/- 14.18) min of plankton 16S rDNA PCR method (P < 0.05). The detection rates of two methods for field water and lung were both 100%. For liver and kidney, the detection rate of plankton 16S rDNA PCR method was both 80%, higher than 40% and 30% of diatom nitric acid digestion method (P < 0.05), respectively.


CONCLUSIONS
The laboratory testing method needs to be appropriately selected according to the specific circumstances in the forensic appraisal of drowning. Compared with diatom nitric acid digestion method, plankton 16S rDNA PCR method has practice values with such advantages as less quantity of samples, huge information and high specificity.
Department of Forensic Medicine, Wenzhou Medical University, Wenzhou 325035, China. hanjunge@wzmc.edu.cn
Jun-ge
JG
Han
School of Forensic Medicine, Wannan Medical College, Wuhu 241002, China.
Cheng-bao
CB
Wang
Department of Forensic Medicine, Wenzhou Medical University, Wenzhou 325035, China.
Xing-biao
XB
Li
Department of Forensic Medicine, Wenzhou Medical University, Wenzhou 325035, China.
Yan-yan
YY
Fan
Department of Forensic Medicine, Wenzhou Medical University, Wenzhou 325035, China.
Xiang-ping
XP
Feng
D000293:Adolescent; D000328:Adult; D004275:DNA, Ribosomal / Q000235:genetics; D017377:Diatoms / Q000145:classification / Q000302:isolation & purification*; D004332:Drowning / Q000175:diagnosis*; D005260:Female; D005554:Forensic Medicine / Q000379:methods; D005618:Fresh Water / Q000032:analysis; D006801:Humans; D007668:Kidney; D008099:Liver; D008168:Lung; D008297:Male; D008875:Middle Aged; D017942:Nitric Acid; D010933:Plankton / Q000235:genetics* / Q000302:isolation & purification; D016133:Polymerase Chain Reaction / Q000379:methods*; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D055815:Young Adult
D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D017942:Nitric Acid