DNA fingerprinting was developed in 1984 by Alec J. Jeffrey at the University of Leicester. It is a technique used to distinguish individuals using DNA samples. It has many applications including identifying criminals, determining paternity, and diagnosing genetic diseases. The process involves isolating DNA from samples, cutting the DNA into fragments of different sizes with restriction enzymes, separating the fragments by size, and comparing fragment patterns to determine matches. DNA fingerprinting revolutionized identification and has been used to solve many criminal cases and identify remains.

2. Who Invented it?
DNA
fingerprinting was
developed in 1984
by Alec. J. Jeffrey at
the University of
Leicester

3. •WHAT IS DNA FINGER PRINTING?
A technique used by scientists to distinguish between
individuals of the same species using only samples of
their DNA

4. • It was used first to discover genetic diseases but now
is also used to help catch criminals
 This method of identification is useful in many
applications such as forensics, paternity testing, and
molecular archeology
 DNA fingerprinting has revolutionized the way the
world identifies biological matches
• DNA fingerprinting may also be used as a system of
personal identification as well as used for medical
purposes in detecting and curing genetic diseases.

5.  The basis of DNA profiling is the use of Restriction
Fragment Length Polymorphisms (RFLPs).
 Single base changes may create or delete specific
restriction sites in DNA.
 These changes are visualized by isolating the DNA,
cutting it with a specific restriction nuclease,
separating the fragments by size on a gel, then
detecting a specific fragment by hybridization to a
complementary probe.

6. Preparation of a DNA fingerprint
Step 1
 Specimen collection
 blood, semen, etc
 easy to contaminate a DNA sample with DNA from
other sources (bacteria, DNA of person collecting
sample)
 DNA is not stable for very long-it degrades
 sunlight
 heat
 moisture

7. STEP 2 : ISOLATION OF DNA
• Cells are broken down to release DNA.
• If only a small amount of DNA is available it can
be amplified using the polymerase chain reaction
(PCR).

8. PCR amplification of DNA
1 strand
of DNA
Heat to
denature
double-
stranded
DNA
Design primers that anneal to STR locus
Amplify all the regions of the chromosome
where the STRs exist.
STR locus
STR locus

9. PCR allows you to make
millions of copies of the
STR region from a
single copy of DNA you
recovered from crime
scene.

10. STEP 3:
CUTTING,SIZING AND SORTING
 Special enzymes called restriction enzymes are used to
cut the DNA at specific places
 Each restriction enzyme cuts DNA at a specific
base sequence.

11.  The sections of DNA that are cut out are called
restriction fragments.
 This yields thousands of restriction fragments of all
different sizes because the base sequences being cut
may be far apart (long fragment) or close together
(short fragment).

12. STEP 4 :
 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.

13.  A radioactive
material is added
which combines with
the DNA fragments
to produce a
fluorescent image.

14. Transfer of DNA to nylon
The distribution of DNA pieces
is transferred to a nylon sheet
by placing the sheet on the gel
and soaking them overnight

15.  In order to find a specific VNTR sequence on a single
strand of DNA, a probe made from the complementary
sample sequence must be labeled with aradioactive
compound.
 The probe is then able to bond to the DNA, and by
using the radioactive tag on the probe, the location of
the attached probe may be identified.

16. LABELLING OF DNA

17. A visual signal is produced when
the different probes anneal (bind)
to the complementary sequence in
the DNA sample

18. Practical Applications of DNA
Fingerprinting
 1.Paternity and Maternity
 person inherits his or her VNTRs from his or her
parents
 Parent-child VNTR pattern analysis has been used to
solve standard father-identification cases

19. No longer necessary
with PCR technology
PCR amplification,
then DNA fingerprinting

20. 2. Criminal Identification and
Forensics
 DNA isolated from blood, hair, skin cells, or other
genetic evidence left at the scene of a crime can be
compared
 FBI and police labs around
the U.S. have begun to use
DNA fingerprints to link suspects
to biological evidence –
blood or semen stains, hair,
or items of clothing

21. Simpson/Goldman Murder
 Pretrial hearings announced that blood collected at
crime scene matched that of O.J.s
 Defense argued that contamination could have occurred
during sample collection and between collection of
different samples
 Technician admitted mislabeling samples
 Possibility that evidence might be tainted was obvious to
both the court and the jury
 DNA evidence was not allowed as evidence
 When rules of evidence are not followed, DNA samples
lose their value in court.

22. 3. Personal Identification
 The notion of using DNA fingerprints as a sort of
genetic bar code to identify individuals has been
discussed
 4.Diagnosis of Inherited Disorders
 diagnose inherited disorders in both prenatal and
newborn babies
 These disorders may include cystic fibrosis,
hemophilia, Huntington's disease, familial
Alzheimer's, sickle cell anemia, thalassemia, and
many others.

23. 5.Developing Cures for Inherited
Disorders
 By studying the DNA fingerprints of relatives who
have a history of some particular disorder
 identify DNA patterns associated with the disease
 6.identification of Chinese medicine
 The Hong Kong Baptist University was able to use
DNA fingerprinting to identify the Chinese
medicine—Lingzhi in 2000

24. 6.MOLECULAR ARCHEOLOGY
•“Tyrolean Ice-Man”, who was
found in
the Alps, and the mummies of
Egypt found in the dry desert.

25. •The ice man was found to
be around 5300 years old, and DNA was
extracted from the remains of his gut which
found small traces of food that he ate (Ice
Man, 2005).
•This was one of the most historic
archeological discoveries in the last century.

26.  DNA evidence has shown that the majority of
bison herds have some domestic livestock as
ancestors.
 No outward (phenotypic) evidence that this is
the case, however.

27. COMBINED DNA INDEX SYSTEM

28.  CODIS identifies 13 markers, plus Amelogenin (AMEL) to determine sex:[2]
 CSF1PO
 D3S1358
 D5s818
 D7s820
 D8S1179
 D13s317
 D16s539
 D18s51
 D21s11
 FGA
 THO1
 TPOX
 vWA
 These markers do not overlap with the ones commonly used forgenealogical
DNA testing. Some may be indicative of genetic diseases.[3]
 [edit]Indices and database structure

29. DNA FINGER PRINTS
MAY ONE DAY BE OUR NATIONAL ID CARDS