2013 Fiscal Year Final Research Report

Development of the methods for the Diatom tests utilizing DNA binding ability of frustle

Research Project

Project/Area Number	23590854
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Research Field	Legal medicine
Research Institution	Oita University
Principal Investigator	SEO Yasuhisa 大分大学, 医学部, 助教 (80187830)
Co-Investigator(Kenkyū-buntansha)	KISHIDA Tetsuko 大分大学, 医学部法医学講座, 教授 (50136793) UCHIDA Tomohisa 大分大学, 医学部法医学講座, 助教 (70381035)
Project Period (FY)	2011 – 2013
Keywords	溺死 / プランクトン / 珪藻 / DNA
Research Abstract	We have focused on the DNA-binding abilities of the diatom frustule, which is constructed of silica, in the presence of chaotropic ions, in an attempt to devise a better forensic test for diatoms. It is proved possible to capture diatoms via lambda DNA using silica-coated magnetic beads followed by isolation and purification from the Mag beads. For purification of diatoms from the blood, DNA binding ability of diatom frustule in the presence of chaotropic agent was utilized. The procedure is basically same as commonly used method for DNA purification from the blood as Proteinase K treatment and denaturation using chaotropic agent. Under this condition, the DNA adsorbed to the diatom and formed DNA/diatom complex. DNA/diatom complex was simply recovered ethanol precipitation and then the DNA was fragmented using DNase. we also developed and evaluated a method for staining diatoms that exploits the DNA binding ability of silica.