title: Relationship between DNA degradation ratios and the number of loci detectable by STR kits in extremely old seminal stain samples.
abstract: The relationships between DNA degradation ratios and the number of detected loci were explored in extremely old seminal stains evaluated using three short tandem repeat (STR) kits: the AmpFlSTR® Identifiler™ PCR Amplification Kit (Identifiler), the AmpFlSTR® Yfiler™ PCR Amplification Kit (Yfiler), and the AmpFlSTR® MiniFiler™ PCR Amplification Kit (MiniFiler). DNA degradation ratios based on 41, 129, and 305bp DNA fragments were calculated (129:41 and 305:41), and the relationships between the ratios and storage duration were also explored. Using the Identifiler kit, the number of loci detected was strongly correlated with the 129:41 ratio (r=0.887), whereas the correlation with the 305:41 ratio was moderate (r=0.656). Using the Yfiler kit, the DYS385 amplicon was detected in all samples, suggesting that DYS385 may be resistant to degradation. The number of detected loci was strongly correlated with the 129:41 ratio (r=0.768), and moderately so with the 305:41 ratio (r=0.515). MiniFiler detected at least seven loci in all samples. In samples that did not yield full profiles, the undetected loci were D7S820 and D21S11, or D21S11 only, suggesting that these loci might be easily degraded. The number of loci detected using STR kits correlated with the DNA degradation ratios. In particular, the 129:41 ratio was particularly useful for estimating the number of loci detectable by STR kits. On the other hand, we suggest that storage duration cannot be accurately estimated using DNA degradation ratios; these ratios were not strongly correlated with storage duration (129:41; r=-0.698, 305:41; r=-0.550). However, the ratios may allow the identification of samples that have been stored for more than 40years.
authors.affiliation: Department of Forensic Medicine, Saitama Medical University, 38 Morohongo, Moroyama, Saitama 350-0495, Japan. Electronic address: ms2_hara@saitama-med.ac.jp.
authors.forename: M
authors.initials: M
authors.lastname: Hara
authors.affiliation: Forensic Medicine, Juntendo University School of Medicine, 2-1-1, Hongo, Bunkyo-Ku, Tokyo 113-8421, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nakanishi
authors.affiliation: Department of Forensic Medicine, Saitama Medical University, 38 Morohongo, Moroyama, Saitama 350-0495, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Takahashi
authors.affiliation: Department of Legal Medicine, Graduate School of Medicine, Gifu University, 1-1, Yanagito, Gifu 501-1194, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Nagai
authors.affiliation: Department of Legal Medicine and Bioethics, Graduate School of Medicine, Nagoya University, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Department of Forensic Medicine, Saitama Medical University, 38 Morohongo, Moroyama, Saitama 350-0495, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yoneyama
authors.affiliation: Forensic Medicine, Juntendo University School of Medicine, 2-1-1, Hongo, Bunkyo-Ku, Tokyo 113-8421, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Saito
authors.affiliation: Department of Forensic Medicine, Saitama Medical University, 38 Morohongo, Moroyama, Saitama 350-0495, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Takada
mesh_terms: D053836:DNA Degradation, Necrotic; D016172:DNA Fingerprinting / Q000295:instrumentation; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats; D012661:Semen; D013997:Time Factors
keywords: DNA degradation; Identifiler kit; MiniFiler kit; Short tandem repeat; Yfiler kit