Download dna-deoxyribonucleic acid

FINGERPRINTING A TOOL FOR
IDENTIFICATION
DNA Fingerprinting
or
DNA Profiling
A method of Forensic identification
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
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.
DNA-DEOXYRIBONUCLEIC ACID
A
T
G
C
C
G
A
T
T
A
G
C
T
A
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
DNA Evidence
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.
Nucleus
Single Cell
DNA
Genome organization
DNA
mRNA
Protein
Chromosome
Nucleus
Cell
Human Genome
Human Genome
Mitochondrial
Nuclear
Coding
5%
Non Coding
95%
Non Repetitive
70- 75%
Repetitive
25- 30%
Interspersed
10- 15%
SINES
<500bp
Tandem
10%
LINES
>500bp
Tandem Repeat Genes
Macro satellites
RU: 2- Nx000
Cryptic satellites
Satellites
5%
Midi satellites
Mini satellites
RU: 9- 100bp
Micro satellites
RU: 2- 7bp
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
Simple paternity
– 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:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
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
APPLICATIONS
•
d) Identification of mutilated bodies (Fake encounters/
of Skeletal Remains
•
e) Parentage Disputes/ Baby Sweeping Cases/ Missing Identity
•
F) Burglary/Threatening/Crime Scene Investigation etc .
Identification
Soft Tissue
CASE DNA SAMPLES FROM DIFF. SOURCES
Saliva
Seminal Fluid
V.S
Saliva
Bones
Cig. Butts