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Published byVanessa Barnett Modified over 9 years ago
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Fingerprints have been used since 1901 Fingerprints? DNA Fingerprints ! DNA Fingerprints since 1986
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Examples of DNA in the News President Clinton & Monica Saddam Hussein Identification
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Identification of WTC Victims Examples of DNA in the News President Jefferson & Hemings
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内容 Part A. Overview of Forensic DNA Analysis Part B. Short Tandem Repeats(STR) & STR-PCR Part C. Y Chromosome & Forensic Science Outline of Presentation
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Two Purpose of Forensic DNA Analysis Four Applications of Forensic DNA Analysis Overview of Forensic DNA Analysis Part A
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Purpose of Forensic DNA Analysis Personal Identification Paternity Testing Judicial Law Enforcement Laboratory
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Applications of Forensic DNA Testing Identify a person Exclude suspects Criminal scene Suspect1 Suspect2 Suspect3 Matching suspect with evidence
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Applications of Forensic DNA Testing ? Missing persons investigations
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Applications of Forensic DNA Testing Paternity testing - identifying father
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Applications of Forensic DNA Testing Mass disasters - putting pieces back together
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Personal Identification Paternity Testing Matching suspect with evidence Missing persons investigations Paternity testing - identifying father Mass disasters - putting pieces back together 1. Purpose of Forensic DNA Analysis 2. Applications of Forensic DNA Testing 2P 3M1P Summary for Part A
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Coming soon……
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Part B Short Tandem Repeats(STR) & STR-PCR The Molecular Structure of DNA What is Short Tandem Repeats(STR)? The Allele Nomenclature of STR The Nomenclature of STR The Principles of STR-PCR Application of STR-PCR
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The Molecular Structure of DNA homologous
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Short Tandem Repeats (STRs) …… Individual 1 Individual 2 Individual 3 …CTAGTCGT(GATA)(GATA)(GATA)GCGATCGT… …CTAGTCGT(GATA)(GATA)(GATA) (GATA) GCGATCGT… …CTAGTCGT(GATA)(GATA)(GATA) (GATA) (GATA) GCGATCGT… The repeat region is variable between samples while the flanking regions where PCR primers bind are constant
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The number of repeat unit Short Tandem Repeats (STRs) 7 repeats 8 repeats AATG Allele Nomenclature 8 7
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TCAT repeat unit STR Sequence from GenBank
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D5S818 D21S11 D13S317 D7S820 D16S539D18S51 D8S1179 D3S1358 Nomenclature of STR D10S2325 D12S391 D1S549 DYS630 DXS1056
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Target Region for STR-PCR A process mediated by a DNA polymerase that can yield millions of copies of a desired DNA sequence Polymerase Chain Reaction (PCR)
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STR with the Polymerase Chain Reaction (PCR)
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Applications of STR-PCR Father’s Sperm Mother’s Egg Child’s Cell Our DNA Comes from our Parents
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Applications of STR-PCR Family Inheritance of STR Alleles (D13S317) Suspect Father Confirmed Mother 11-14 12-14 8-14 11-12 8-12
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Locus Suspected-Father Confirmed-Mother Child D8S1179 13-16 12-13 12-14 D5S818 9-11 10-11 10-12 D1S549 13-14 14-15 13-14 D3S1754 14-15 13-13 13-14 Applications of STR-PCR D8S1179 13-16 12-13 12-14 D5S818 9-11 10-11 10-12 …… × × Exclusion !
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Coming soon……
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Part C Y Chromosome & it’s Application in Forensic Science
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The Human Genome Characteristics of Human Y chromosome Father to son & Male-specific Dad made you a boy or girl
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Y chromosome’s application in Forensic Science Deficiency Paternity Testing Sexual Assault Cases Historical Investigations ?
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Thomas Jefferson fathered slave’s children
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Failure to Exclude Jefferson as Eston Hemings’ Father ? × Identical !
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SUMMARY 1. Purpose of Forensic DNA Analysis 2. Applications of Forensic DNA Testing 3. What is Short Tandem Repeats(STR)? 4. The Principles of PCR 5. Characteristics of Human Y chromosome 2P 3M1P
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Questions ? What’s the difference between Autosomal STR and Y-chromosomal STR?
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Thanks for your attention!
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