Original scientific paper
https://doi.org/10.3325/cmj.2017.58.4
Comparison of preprocessing methods and storage times for touch DNA samples
Hui Dong
; Key Laboratory of Forensic Genetics, Beijing Engineering Research Center of Crime Scene Evidence Examination, Institute ofForensic Science, Ministry of Public Security, Beijing, China
Jing Wang
; Key Laboratory of Forensic Genetics, Beijing Engineering Research Center of Crime Scene Evidence Examination, Institute ofForensic Science, Ministry of Public Security, Beijing, China
Tao Zhang
; Key Laboratory of Forensic Genetics, Beijing Engineering Research Center of Crime Scene Evidence Examination, Institute ofForensic Science, Ministry of Public Security, Beijing, China
Jian-ye Ge
; Human Identification Division Thermo Fisher Scientific, South San Francisco, CA, USA
Ying-qiang Dong
; Key Laboratory of Forensic Genetics, Beijing Engineering Research Center of Crime Scene Evidence Examination, Institute ofForensic Science, Ministry of Public Security, Beijing, China
Qi-fan Sun
; Key Laboratory of Forensic Genetics, Beijing Engineering Research Center of Crime Scene Evidence Examination, Institute ofForensic Science, Ministry of Public Security, Beijing, China
Chao Liu
; Guangzhou Forensic Science Institute, Guangdong Province Key Laboratory of Forensic Genetics, Guangzhou, China
Cai-xia Li
; Key Laboratory of Forensic Genetics, Beijing Engineering Research Center of Crime Scene Evidence Examination, Institute ofForensic Science, Ministry of Public Security, Beijing, China
Abstract
Aim To select appropriate preprocessing methods for different substrates by comparing the effects of four different preprocessing methods on touch DNA samples and to determine the effect of various storage times on the results of touch DNA sample analysis.
Method Hand touch DNA samples were used to investigate the detection and inspection results of DNA on different substrates. Four preprocessing methods, including the direct cutting method, stubbing procedure, double swab technique, and vacuum cleaner method, were used in this study. DNA was extracted from mock samples with four different preprocessing methods. The best preprocess protocol determined from the study was further used to compare performance after various storage times. DNA extracted from all samples was quantified and amplified using standard procedures.
Results The amounts of DNA and the number of alleles detected on the porous substrates were greater than those on the non-porous substrates. The performances of the four preprocessing methods varied with different substrates. The direct cutting method displayed advantages for porous substrates, and the vacuum cleaner method was advantageous for non-porous substrates. No significant degradation trend was observed as the storage times increased.
Conclusion Different substrates require the use of different preprocessing method in order to obtain the highest DNA amount and allele number from touch DNA samples. This study provides a theoretical basis for explorations of touch DNA samples and may be used as a reference when dealing with touch DNA samples in case work.
Keywords
Hrčak ID:
181400
URI
Publication date:
15.2.2017.
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