Comparative Analysis between Diatom Nitric Acid Digestion Method and Plankton 16S rDNA PCR Method / 法医学杂志

ABSTRACT

Objective To com pare and explore the application value of diatom nitric acid digestion method and plankton 16S rDNA PCR method for drow ning identification. Methods Forty drow ning cases from 2010 to 2011 were collected from Department of Forensic Medicine of Wenzhou Medical University. Sam ples including lung, kidney, liver and field water fromeach case were tested with diatom nitric acid digestion method and plankton 16S rDNAPCR method, respectively. The Diatom nitric acid digestion method and plankton 16S rDNAPCR method required 20 gand 2g of each organ,and 15 mL and 1.5 mL of field water, respectively. The inspection time and detection rate were com pared between the two methods. Results Diatom nitric acid digestion method m ainly detected two species of diatom s, Centriae and Pennatae, while plankton 16S rDNA PCR method am plified 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. Conclusion The laboratory testing method needs to be appropriately selected according to the specific circum stances in the forensic appraisal of drow ning. Com pared with diatom nitric acid digestion method, plankton 16S rDNA PCR method has practice values with such advantages as less quantity of sam ples, huge inform ation and high specificity.