title: A comparison of four methods for PCR inhibitor removal.
abstract: Biological samples collected from the crime scenes often contain some compounds that can inhibit the polymerase chain reaction (PCR). The removal of PCR inhibitors from the extracts prior to the PCR amplification is vital for successful forensic DNA typing. This paper aimed to evaluate the ability of four different methods (PowerClean® DNA Clean-Up kit, DNA IQ™ System, Phenol-Chloroform extraction and Chelex®-100 methods) to remove eight commonly encountered PCR inhibitors including: melanin, humic acid, collagen, bile salt, hematin, calcium ions, indigo and urea. Each of these PCR inhibitors was effectively removed by the PowerClean® DNA Clean-Up kit and DNA IQ™ System as demonstrated by generating more complete short tandem repeat (STR) profiles from the cleaned up inhibitor samples than from the raw inhibitor samples. The Phenol-Chloroform extraction and Chelex®-100 methods, however, could only remove some of eight PCR inhibitors. Our results demonstrated that the PowerClean® DNA Clean-Up kit and DNA IQ™ System were very effective for the removal of known PCR inhibitors that are routinely found in DNA extracts from forensic samples.
authors.affiliation: Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, No. 13, Hangkong Road, Wuhan 430030, China.
authors.forename: Qingqing
authors.initials: Q
authors.lastname: Hu
authors.affiliation: Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, No. 13, Hangkong Road, Wuhan 430030, China.
authors.forename: Yuxuan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, No. 13, Hangkong Road, Wuhan 430030, China.
authors.forename: Shaohua
authors.initials: S
authors.lastname: Yi
authors.affiliation: Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, No. 13, Hangkong Road, Wuhan 430030, China. Electronic address: huangdaixin@mails.tjmu.edu.cn.
authors.forename: Daixin
authors.initials: D
authors.lastname: Huang
mesh_terms: D004247:DNA / Q000032:analysis / Q000235:genetics / Q000302:isolation & purification*; D016172:DNA Fingerprinting / Q000379:methods; D053803:Forensic Genetics / Q000379:methods / Q000592:standards; D006801:Humans; D020014:K562 Cells; D016133:Polymerase Chain Reaction / Q000379:methods* / Q000592:standards; D011933:Reagent Kits, Diagnostic; D013048:Specimen Handling / Q000379:methods*
chemical_list: D011933:Reagent Kits, Diagnostic; D004247:DNA
keywords: Chelex(®)-100; DNA IQ™; Forensic DNA analysis; PCR inhibition; Phenol–Chloroform; PowerClean(®) DNA Clean-Up