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DNA profiling, also known as DNA fingerprinting, is a method of forensic identification where a unique DNA pattern is generated to individualize a person, similar to fingerprinting. This technology has various applications in forensic investigations.
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DNA Profiling A method of Forensic identification DNA Fingerprintingor DR.I.HAQUE CFSL,MHA
What is DNA Profiling? Using different state- of the- art techniques a definite DNA pattern is generated to individualise the person just like “ Fingerprinting”. This unique pattern of individual DNA is called DNA Profiling OR DNA Fingerprinting
1 DNA-DEOXYRIBONUCLEIC ACID DNA
Simple DNA Structure • The phosphate and sugar form the backbone of the DNA molecule, whereas the bases form the “rungs”. • There are four types of nitrogenous bases.
A A A T T T T A C C C DNA-DEOXYRIBONUCLEIC ACID G G G
DNA DNA Gene Protein Trait
DNA Fingerprint Basics • Different individuals carry different alleles. • Most alleles useful for DNA fingerprinting differ on the number of repetitive base sequences they contain. • Restriction enzymes are used to cut the DNA along these repetitive sequences.
Who Invented it? • The process of DNA fingerprinting was invented by Alec Jeffreys at the University of Leicester in 1985. • He was knighted in 1994. Alec Jeffreys
VICTIM? Rape Murder Burglary Violent Crimes CRIME SCENE CRIMINAL? A TRIANGLE OF CRIME
Locard Exchange Theory The Locard Exchange Theory states that when two objects come into contact, there will be an exchange of material. This may involve transfer between two individuals, an individual and the crime scene or between the crime scene and another location. DNA Evidence
Nucleus Single Cell
Genome organization DNA DNA mRNA Protein Chromosome Cell Nucleus
Applications … Non-coding region individual identification / forensic applications, etc. genetic diversity chromosome rearrangements chromosomal origin association studies linkage analysis marker-assisted selection (MAS) livestock and crop improvement assessment and management of biodiversity molecular taxonomy Coding region genetic diseases disease diagnostics pharmacogenomics association studies
First DNA Cases: By Dr. A. Jeffreys FORENSIC FIRSTS: DNA Profiling and the Colin Pitchfork Case Colin Pitchfork, aka The Black Pad Killer
Blood Semen/ sperm Body tissue/ skin Bone/ bone marrow Hair/ hair roots Saliva/ bite marks Urine Teeth/dental Fecal material Mucous
DNA FINGERPRINTING IS POSSIBLE FROM Biological Stains on Any Matrix Like- Saliva, Semen, Blood on: • CLOTHINGS (Pants, shirts, sarees, salwar-kurta,blouses, under garments, etc.) • Beddings (Blankets, Bed Sheets, Pillow Covers) • Carpets • Cars and Car seats • Guns • Shoes • Cigarette Butts • Hairs • Bones • Teeth • Finger Nail • Tissues • Blood Stains • Semen Stains
15. Vaginal Secretions 16. Chewing Gum 17. Razor Blades 18. Tooth Brush 19. Stamps and Envelops 20. Ear Rings 21. Nasal Secretions 22. Ear Wax 23. Watches 24. Coffee Cups, Coke Cans, Beer Bottles,etc. 25. Ski Masks (Saliva and Hair) 26. Caps (Hairs) 27. Shirts (Neck area for sweat) 28. Tooth Picks 29. Eye Glasses & Lenses
Femur Skull Human Bite Mark
FORENSIC APPLICATIONS • a) Murder/Attempt to murder • b) Rape/Sodomy/other sexual offences • c) Accidents/mass Disaster • d) Identification of mutilated bodies (Fake encounters/ Identification of Skeletal Remains • e) Parentage Disputes/ Baby Sweeping Cases/ Missing Identity • F) Burglary/Threatening/Crime Scene Investigation etc . APPLICATIONS
Soft Tissue CASE DNA SAMPLES FROM DIFF. SOURCES Saliva Seminal Fluid Saliva V.S Bones Cig. Butts