This slides helps to know DNA finger printing

1. DNA FINGERPRINTING

2. Deoxyribonucleic acid (DNA) in the Cell
cell nucleus
chromosome
Double stranded
DNA molecule

3. Double helix

4. The chemical structure of everyone's DNA is the same. The
only difference between people (or any animal) is the order of
the base pairs.
•Some regions- no genetic information -JUNK DNA
vary enormously
•short sequence of DNA has been repeated a number of times-
Variable number tandem repeats –VNTR/STR
•DNA Fingerprinting –used to distinguish individuals, method
of identification that compares fragments of DNA called DNA
typing.
DNA Fingerprinting-Definition

5. Genetic continuity

6. Brief History of DNA TypingBrief History of DNA Typing
1954 - Watson & Crick described the structure of
DNA (Nobel Prize)
1984- DNA fingerprinting developed by Alec Jeffreys
1985 - Mullis developed protocol for polymerase
chain reaction (PCR) (Nobel Prize)

7. Sources of DNA

8. STEPS IN DNA PROFILING
Extraction of DNA
DNA amplification by PCR
Electrophoresis on Agarose gels
Genetic analyser
Analysis and interpretation of results

11. DNA is the choice for individual identification
Discrimination/Distinguishing
No two people except identical twins (monozygotic) will share the same genetic
blueprint. Identical twins are essentially clones.
Genetic Continuity
The DNA found at birth in each of our cells will contain the same genetic
blueprint that will be present in our cells at death. In addition genetic continuity
extends across generations allowing family members to be identified through
similar DNA genotypes.
Sensitivity
A few drops of blood, a buccal swab or a small semen stain will generally contain
ample amounts of DNA for analysis.
Stability
The DNA molecule resembles a twisted ladder comprising three chemical
components to form a phosphate-sugar backbone joined by rungs of organic bases
(adenine, guanine, cytosine and thymine).

12. Real world applications
 Which one matches?
Food identification
Crime scene Human remains
Human relatedness
Anthropology studies
Disease-causingorganisms
Paternity
Monitoring transplants
Animal relatedness

13. Most Important cases solved by this
technology
Fast track DNA analysis confirms the Saddam’s
identity
Rajiv Gandhi assassination case –Elusive criminals
like Sivarasan and 'Dhanu', have been tracked by DNA
fingerprinting technique
Naina Sahni 'tandoor' murder, proved that the half
charred remains were indeed of Naina

14. DNA is a
powerful tool,
both for
conviction and
EXONERATION of
suspects.

15. We can use –DNA Fingerprinting
•DNA identifications after
the 9/11 World Trade
Center attack -this
technique facilitated the
identification of 1594 of
the 2749 victims)
• Tsunami disaster – 2004

16. Size Mother Baby Father
Hypothetical gel pattern
for microsatellite heterozygous
for all individuals.
DNA fingerprint of Typical paternity case