Fingerprints have been used since 1901 Fingerprints? DNA Fingerprints ! DNA Fingerprints since 1986

Examples of DNA in the News President Clinton & Monica Saddam Hussein Identification

Identification of WTC Victims Examples of DNA in the News President Jefferson & Hemings

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

Two Purpose of Forensic DNA Analysis Four Applications of Forensic DNA Analysis Overview of Forensic DNA Analysis Part A

Purpose of Forensic DNA Analysis Personal Identification Paternity Testing Judicial Law Enforcement Laboratory

Applications of Forensic DNA Testing Identify a person Exclude suspects Criminal scene Suspect1 Suspect2 Suspect3 Matching suspect with evidence

Applications of Forensic DNA Testing ? Missing persons investigations

Applications of Forensic DNA Testing Paternity testing - identifying father

Applications of Forensic DNA Testing Mass disasters - putting pieces back together

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

Coming soon……

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

The Molecular Structure of DNA homologous

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

The number of repeat unit Short Tandem Repeats (STRs) 7 repeats 8 repeats AATG Allele Nomenclature 8 7

TCAT repeat unit STR Sequence from GenBank

D5S818 D21S11 D13S317 D7S820 D16S539D18S51 D8S1179 D3S1358 Nomenclature of STR D10S2325 D12S391 D1S549 DYS630 DXS1056

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)

STR with the Polymerase Chain Reaction (PCR)

Applications of STR-PCR Father’s Sperm Mother’s Egg Child’s Cell Our DNA Comes from our Parents

Applications of STR-PCR Family Inheritance of STR Alleles (D13S317) Suspect Father Confirmed Mother

Locus Suspected-Father Confirmed-Mother Child D8S D5S D1S D3S Applications of STR-PCR D8S D5S …… × × Exclusion ！

Coming soon……

Part C Y Chromosome & it’s Application in Forensic Science

The Human Genome Characteristics of Human Y chromosome Father to son & Male-specific Dad made you a boy or girl

Y chromosome’s application in Forensic Science  Deficiency Paternity Testing  Sexual Assault Cases  Historical Investigations ?

Thomas Jefferson fathered slave’s children

Failure to Exclude Jefferson as Eston Hemings’ Father ? × Identical !

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

Questions ? What’s the difference between Autosomal STR and Y-chromosomal STR?

Thanks for your attention!