Introduction to DNA fingerprinting

1. DNA
FINGERPRINTING
Group 8
Michila Fernando
and
Sureshni Fernando

2. A technique that detects mini-satellites
in the genome to produce a pattern
unique to an individual.
Also known as DNA profiling, DNA typing
and genetic fingerprinting.
WHAT IS DNA
FINGERPRINTING?

3. HISTORY
Science of fingerprinting was 1st
used by Sir William Herschel as a
method of identification in 1858
and in 1897 in India.
The DNA fingerprinting technique
was invented by Alec Jeffreys
(1984) at Leicester University,
United Kingdom.

4. PRINCIPLE
Human genome consists of non coding proteins
which make up 95% of DNA known as junk DNA.
They can be separated as satellites by density
centrifugation.
In satellites, repetition of bases is in tandem.
According to the length, base composition and
numbers of tandemly repetitive units, it is
divided as micro-satellites and mini-satellites.
At specific loci on the chromosome, the number
of tandem repeats varies between individuals.

5. APPLICATIONS
 To study human lineage
 To diagnose inherited
disorders
 For forensic studies
 To solve
paternity/maternity
disputes

7. TECHNIQUE
1. Extraction of DNA
- from blood, saliva, semen, hair roots by salting
out proteins.
2. Digestion of DNA using restriction enzymes
- Restriction endonucleases recognize palindromic regions and cut DNA
forming sticky or blunt ends.

8. 3. Separation of the DNA fragments using gel electrophoresis
- occurs based on their size, shape, charge and
concentration of the agarose under the influence of an
electric field.
4. Transfer the DNA
- A nitrocellulose membrane or nylon sheet
is placed on the gel and allowed to soak
overnight by southern blotting.

9. 5. Probe labelling
- Complementary
radioactive probes are added
to the membrane and allowed
to hybridize. The excess
probes are washed off.
6. Autoradiography
- Exposed to X-ray film to
allow the variable fragments
to be visualized.

10. DISADVANTAGES
 Collected evidence can be
stored indefinitely
 Criminals are charged and
justice for victims
 Measure individuality
 Develop treatment for
inherited disorders
 Not an obtrusive process
 Infringement of privacy
 Contamination can result
in false conclusions
 False positive and false
negative results
ADVANTAGES

11. SUMMARY

12. REFERENCES
Barh, D. and Azevedo, V. (2017) Omics Technologies and Bio-Engineering, pp. 591-625.
Bioscience Times (2018) DNA Fingerprinting- Principle, Methods, Applications [Online]. Available at:
https://www.biosciencetimes.com/molecular-biology/dna-fingerprinting/276/ (Accessed: 28 August
2019).
Kofanova, O. A., Mathieson, W., Thomas, G. A. and Betsou F. (2014) ‘DNA Fingerprinting: A Quality
Control Case Study for Human Biospecimen Authentication’, Biopreservation and Biobank, 12(2), pp.
151–153 [Online]. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3995361/ (Accessed:
27 August 2019).
Roewer, L., (2013) ‘DNA fingerprinting in forensics: past, present, future’, Investigative Genetics, 4(22)
[Online]. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3831584/ (Accessed: 28 August
2019).
Sciencing (2019) What are Specific Biotechnology Applications for DNA Fingerprinting? [Online].
Available at: https://sciencing.com/specific-biotechnology-applications-dna-fingerprinting-23975.html
(Accessed: 28 August 2019).
Your Article Library (2019) DNA Fingerprinting: Principles and Techniques of DNA Fingerprinting
[Online]. Available at: http://www.yourarticlelibrary.com/dna/dna-fingerprinting-principles-and-
techniques-of-dna-fingerprinting/12211 (Accessed: 28 August 2019).
Yourgenome.org. (2016) What is a DNA fingerprint? [Online] Available at:

13. THANK YOU!