The document summarizes the process of DNA fingerprinting. It discusses how Alec Jeffreys invented the technique in 1985 at the University of Leicester in the UK. DNA fingerprinting involves analyzing variable regions of DNA to generate a unique profile that can identify an individual. It describes how PCR is used to amplify DNA samples and how short tandem repeats are typically analyzed. The document provides an overview of how DNA samples are prepared, labeled, and separated to generate DNA profiles using analytical instruments and software. It also gives some examples of how DNA fingerprinting is used for criminal investigations and establishing biological relationships.

1. BY:- MANTOSH KUMAR
ROLL NO.-BT/12/08

2.  The process of DNA
fingerprinting was
invented by Alec
Jeffreys at the
University of
Leicester in 1985.
 He was knighted in
1994.

3.  The use of DNA sequences to identify
individual persons is called DNA
fingerprinting or DNA profiling.
 Because some part genome are highly variable,
each person DNA sequence is unique and, like
a traditional fingerprinting, provides a
distinctive characteristic that allows
identification.
 Today most DNA FINGERPRINTIG utilizes
microsetallites, or short tandem repeat (STRs)

4.  PCR – used to amplify DNA found at crime
scene into an amount that can be analyzed
 Microsatelliteare typically detected with PCR
 The length of the amplified segment depends on the
number of repeats
• DNA from a person with more repeats will produce
a longer amplified segment than will DNA from a
person with fewer repeats.
• DNA produced is identical to the original sample

6. The Process In a Nutshell
Amplified DNA samples are injected into a
capillary. Fluorescent tags on the DNA
fragments are excited by a laser, the
fluorescence is recorded by a camera, and
this signal is converted into a “peak” by the
computer software.

7. Applied Biosystems 310 Genetic
Analyzer

8. STR data
X, Y,
XY

9.  GeneScan®
 Genotyper® software
 GeneMapper® ID (GMID)
 FMBIO® Analysis Software,
 FMBIO® STaRCall™
 AmpFLSTR™ Profiler Plus™

10.  Used by FBI
 They have taken 13
STR loci
 These system was
used in to know
people who died in
the collapse of world
trade center.

11.  Stage 1:
Cells are broken down to release DNA
 Step 2:
The DNA is cut into fragments using restriction
enzymes
Stage 3:
 Fragments are separated on the basis of size using a
process called gel electrophoresis
Stage 4:
 The pattern of fragment distribution is then
analysed.

12. EcoR I EcoR I EcoR I EcoR I

14. _ +

15. _ +

16. • Eliminate hydrogen bonds with sodium
hydroxide (NaOH)
A C T T G A
T G A A C T

17. • Two methods for transferring DNA to a
membrane
– capillary
– electrophoretic

18.  Immobilize DNA onto a permanent substrate
 Identify DNA sequence (gene) of interest

19.  A probe is a small (25-2000 bp) length of DNA or
RNA
 Complementary to the sequence (gene) of interest
 Labeled for subsequent detection procedures

20.  How do we detect the probe?
 Digoxigenin (DIG)
U

25.  DIG-labeled probes
emitting minute
amounts of light
(chemiluminescence)
 32P-labeled probes
emitting ß-particles
 Autoradiography film
can detect this radiation

27.  DNA profiling is
used to solve crimes
and medical
problems

28.  Blood
 Hair
 Saliva
 Semen
 Body tissue cells
 DNA samples have
been obtained from
vaginal cells after rape
or intercourse.

29.  Colin Pitchfork was the
first criminal caught based
on DNA fingerprinting
evidence.
 He was arrested in 1986
for the rape and murder of
two girls and was
sentenced in 1988.

30. In 2002 Elizabeth Hurley
used DNA profiling to
prove that Steve Bing
was the father
of her child Damien

31. 31

32. Thank you