著者

原 正昭 永井 淳 田村 明敬 山本 敏充 廣重 優二 小川 久恵 引土 知幸 梅田 光夫 川尻 由美 中山 幸治 鈴木 廣一 髙田 綾 石井 晃

出版者

埼玉医科大学

雑誌

基盤研究(C)

巻号頁・発行日

2014-04-01

---

犯罪現場で時々みられる吸血蚊から、個人特定が可能かどうか、また、吸血後の経過時間を推定可能かどうかを目的として行った。2種類の蚊を、被検者計7名に吸血させ、一定時間経過後、殺虫した蚊からDNA抽出し、各抽出DNAを、3種類の増幅長の異なる増幅産物で定量を行った。また、15座位のSTR及びアメロゲニンの型判定を行った。その結果、型判定は吸血後2日経過まで可能で、ピーク高比などから総合的に半日単位の経過時間推定が可能であることが示唆された。17座位のY-STRの型判定結果も同様であった。今後、改良すれば、より精度の高い吸血後経過時間推定が可能であると考えられた。成果の一部は、英文誌に受理された。

著者

廣重 優二 山本 敏充 吉本 高士 石井 晃

出版者

日本法科学技術学会

雑誌

日本法科学技術学会誌 (ISSN:18801323)

巻号頁・発行日

vol.18, no.2, pp.97-111, 2013 (Released:2013-07-30)

参考文献数

26

---

In general, the attachment of human hair sheath is considered as one of the most important factors in detecting STR genotypes from single hair samples. Thus, it is difficult to genotype STRs from naturally shed human hair samples using AmpFℓSTR Identifiler PCR Amplification Kit. In this study, we examined the conditions involved in determining STR genotypes from a single hair root of naturally shed human hair focusing on two kinds of commercially available DNA extraction kits; a QIAamp DNA Micro kit (Micro kit) and an ISOHAIR kit (ISOHAIR kit), and the relationship between the concentration of extracted DNA and the numbers of STR loci genotyped.   As a result, based on the protocol of DNA quantification adopted in the police labs in Japan, the DNA amounts were sufficient to quantify in approximately 28% or 36% of 72 naturally shed human hair samples using a Micro or an ISOHAIR kit, respectively. There was no significant difference in genotyping STRs between the two extraction methods. If a quantitative value was estimated based on a Ct (cycle threshold)-value, the extracted DNA was duplicated to amplify by 28 PCR cycles. Alternatively, if a quantitative value showed “ND (not detected)”, the extracted DNA was performed by duplicate PCR amplification for 32 cycles.   Consequently, in the case of a 28 cycle-amplification, when a quantitative value was more than 0.04 ng/μl, the genotyping result was obtained accurately at almost all loci by both extraction methods. On the other hand, in the case of a 32 cycle-amplification, there was a tendency that more accurate genotypes are obtained by a smaller size of an amplicon except a few loci. It indicated that the accurate genotyping rate should not depend only on the size of PCR products.   Therefore, when a DNA sample shows “ND” as an estimated value, more careful interpretation should be necessary to genotype by increasing PCR cycles to 32, or more strict making decision not to proceed to any PCR amplification should be performed.