title: Isolating Sperm from Cell Mixtures Using Magnetic Beads Coupled with an Anti-PH-20 Antibody for Forensic DNA Analysis.
abstract: Vaginal swabs taken in rape cases usually contain epithelial cells from the victim and sperm from the assailant and forensic DNA analysis requires separation of sperm from these cell mixtures. PH-20, which is a glycosylphosphatidylinositol-anchored hyaluronidase located on the head of sperm, has important functions in fertilization. Here we describe a newly developed method for sperm isolation using anti-PH-20 antibody-coupled immunomagnetic beads (anti-PH-20 IMBs). Optical microscopy and scanning electron microscopy showed the IMBs recognized the head of sperm specifically and exhibited a great capacity to capture sperm cells. However, we found it necessary to incubate the IMB-sperm complex with DNase I before sperm lysis in order to remove any female DNA completely. We compared the sensitivity of anti-PH-20 IMBs in sperm and epithelial cell discrimination to those coated with a different anti-sperm antibody (anti-SP-10, anti-ADAM2 or anti-JLP). Only the anti-PH-20 IMBs succeeded in isolating sperm from cell mixtures at a sperm/epithelial cell ratio of 103:105. Further, our method exhibited greater power and better stability for sperm isolation compared to the traditional differential lysis strategy. Taken together, the anti-PH-20 IMB method described here could be effective for the isolation of sperm needed to obtain a single-sourced DNA profile as an aid to identifying the perpetrator in sexual assault cases.
authors.affiliation: Beijing Engineering Research Center of Crime Scene Evidence Examination, Institute of Forensic Science, Ministry of Public Security, Beijing, People's Republic of China.|Key Laboratory of Forensic Genetics, Institute of Forensic Science, Ministry of Public Security, Beijing, People's Republic of China.
authors.forename: Xing-Chun
authors.initials: XC
authors.lastname: Zhao
authors.affiliation: Beijing Engineering Research Center of Crime Scene Evidence Examination, Institute of Forensic Science, Ministry of Public Security, Beijing, People's Republic of China.|Key Laboratory of Forensic Genetics, Institute of Forensic Science, Ministry of Public Security, Beijing, People's Republic of China.
authors.forename: Le
authors.initials: L
authors.lastname: Wang
authors.affiliation: Beijing Engineering Research Center of Crime Scene Evidence Examination, Institute of Forensic Science, Ministry of Public Security, Beijing, People's Republic of China.|Key Laboratory of Forensic Genetics, Institute of Forensic Science, Ministry of Public Security, Beijing, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Sun
authors.affiliation: Department of Scientific Instruments, the First Research Institute of the Ministry of Public Security, Beijing, People's Republic of China.
authors.forename: Bo-Wei
authors.initials: BW
authors.lastname: Jiang
authors.affiliation: Department of Criminalistics, People's Public Security University of China, Beijing, People's Republic of China.
authors.forename: Er-Li
authors.initials: EL
authors.lastname: Zhang
authors.affiliation: Beijing Engineering Research Center of Crime Scene Evidence Examination, Institute of Forensic Science, Ministry of Public Security, Beijing, People's Republic of China.|Key Laboratory of Forensic Genetics, Institute of Forensic Science, Ministry of Public Security, Beijing, People's Republic of China.
authors.forename: Jian
authors.initials: J
authors.lastname: Ye
mesh_terms: D000906:Antibodies / Q000378:metabolism*; D002469:Cell Separation / Q000379:methods*; D004247:DNA / Q000032:analysis* / Q000235:genetics; D003851:Deoxyribonucleases / Q000378:metabolism; D005260:Female; D005554:Forensic Medicine / Q000379:methods*; D006801:Humans; D018189:Immunomagnetic Separation / Q000379:methods*; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D008863:Microspheres; D013077:Sperm Head; D013094:Spermatozoa / Q000166:cytology*
chemical_list: D000906:Antibodies; D004247:DNA; D003851:Deoxyribonucleases