DNA Technology provides a tool in the hands of Police/Law with a potential “genetic eyewitness”, thus linking crime with criminal and regarded as the standard of excellence for the development of impartial, unbiased scientific evidence to ensure accuracy, transparency and fairness in criminal justice system.

1. Forensic and Medico-legal applications of
DNA Fingerprinting
Dr. Jyoti M. Ganer. (Baragi)
Assistant Professor
Dept. of Agada Tantra Evam Vyavahara
Ayurveda

2. Scientific Tools used in Criminal
investigation in the Recent days:
Electronic Surveilance
Lie Detector or Polygraphic Test
Brain Mapping Test (P-300 Test)
Narco-Analysis Test (In rare
cases)
DNA Fingerprinting

3. What is DNA ?
DNA or deoxyribonucleic
acid, is the hereditary material
in humans and almost all
other organisms. Nearly every
cell in a persons body has the
same DNA.
The DNA of each individual
does not change during his
lifetime.

4. What is DNA fingerprinting ?
The chemical structure of everyone
DNA is same but the difference lies in
the base pairs.
They are able to determine whether
two DNA samples are from the same
person, related people, or non-related
people.
DNA fingerprinting has the ability to
link physical evidence found at a
crime scene to a single person
(criminal).
It is considered as unbiased scientific
evidence to ensure accuracy,

5. Who Invented it ?
The process of DNA
fingerprinting was
invented by Alec Jeffreys
at the University of
Leicester in 1985.

6. Biological materials used for DNA fingerprinting
Blood
Hair
Saliva
Semen
Body tissue cells
Vaginal cells on the condom

7. Stages of DNA fingerprinting
Stage 1: Isolation of
DNA
DNA must be
recovered from cells or
tissue. Only a small
amount of blood, hair,
or skin is needed.

8. Stage 2: Cutting & Sizing
The DNA is cut into
fragments using
restriction enzymes.
Each restriction enzyme
cuts DNA at a specific
base sequence.
Stages of DNA fingerprinting

9. Stage 3: Sorting
Fragments are separated
on the basis of size using
a process called gel
electrophoresis.
DNA fragments are
injected into wells and an
electric current is applied
along the gel.
Stages of DNA fingerprinting

10. Stage 4: Transfer of DNA
to Nylon
The DNA pieces are
transferred to a nylon
sheet by placing the
sheet on the gel and
soaking them
overnight.
Stages of DNA fingerprinting

11. Stage 5: Probing
Adding radioactive or
colored probes to the
nylon sheet produces a
pattern, which is the
DNA Fingerprint. Each
probe only sticks to one
or two specific places on
the sheet.
Stages of DNA fingerprinting

12. Stage 6: DNA
Fingerprint
The final DNA
fingerprint is built by
using several probes.
It resembles bar codes.
Stages of DNA fingerprinting

13. Application of DNA fingerprinting
Crime Investigations: like murder, sexual
offences like rape, assaults, robbery, house
breaking and burglary, hoax crime and
kidnapping etc.
Medical Problems: like paternity-maternity
disputes: In case of adultery, lost child and
exchange of babies in the Hospitals.
Natural and Man-made Disasters:
Identification of mass casualties during
earthquakes, floods, air-crashes, train accidents,
Bomb blast, fire, war victims especially in
identification of the mutilated bodies.

14. DNA Technology provides a tool
in the hands of Police/Law with a
potential “genetic eyewitness”, thus
linking crime with criminal and
regarded as the standard of
excellence for the development of
impartial, unbiased scientific
evidence to ensure accuracy,
transparency and fairness in
criminal justice system.
Conclusion

15. “DNA fingerprinting only provides the
proof of identity and not the proof of guilt”